How to Edit a Block in AutoCAD?

By default, double-clicking on the block opens either the Properties dialog box or the Block Editor.

Edit Block In-Place

To edit a block in-place, do any of the following:

  • Right-click on the block and select Edit Block In-Place.
  • Use the command REFEDIT to open the in-place block editor for a selected block. After editing, use the REFCLOSE command to close it. 
  • To change the double-click function to the In-Place Block Editor, follow these steps:
  1. At the command prompt, enter CUI.
  2. In the Customize User Interface dialog box, click the Customize tab.
  3. On the Customize tab, under Customizations in All CUI Files, expand the Main CUI File > Double-Click Actions > Block.
  4. Click on the Block – Double Click action.
  5. In the Properties section, substitute the existing Macro entry with the following:


  1. Click OK.
  2. Set the BLOCKEDITLOCK variable to 1.

Note: If the BLOCKEDITLOCK system variable is set to 0, double-clicking on a block will open the Block Editor.

Block Editor

The Block Editor provides an easy way to define and edit blocks and to add dynamic behaviors to block definitions.

In the Block Editor, you can

  • Define a block
  • Add an action parameter
  • Add a geometric or dimensional constraint (not available in AutoCAD LT)
  • Define attributes
  • Manage visibility states
  • Test and save the block definition

Note: If you are working with dynamic blocks, keep the Command window displayed in the Block Editor, as it displays many prompts for many aspects of creating dynamic behaviors.

Modify a Block Definition

There are several methods for redefining a block definition. The method you choose depends on whether you want to make changes in the current drawing only or in a source drawing also.

  • Modify the block definition in the current drawing.The Block Editor provides the easiest way to modify a block in the current drawing. The changes you make and save in the Block Editor replace the existing block definition, and all references to that block in the drawing are immediately updated.An alternative way to modify a block definition is to create a new block definition, but enter the name of the existing block definition. You can insert and explode an instance of the original block and then use the resulting objects in creating the new block definition.
  • Modify the block definition in the source drawing and reinsert it into the current drawing.Updating a block that was created in another drawing and then inserted into the current drawing does not trigger an automatic update (unlike inserting xrefs). To update a block that has been updated in another drawing, you must reinsert it.
  • Update a block definition that originated from an inserted drawing file.Block definitions created in your current drawing by inserting a drawing file are not updated automatically when the original drawing is modified. You must insert the drawing again to update a block definition from the drawing file.
  • Update a block definition that originated in a library drawing (advanced).Inserting a block using DesignCenter does not overwrite an existing block definition. To insert a block definition that has been updated in a block library, for example, use WBLOCK to save the block as a separate drawing. Then, insert the drawing to overwrite the outdated block definition.Note: Block descriptions are stripped off when using INSERT. Use the Clipboard to copy and paste a block description displayed in the Block Definition dialog box from one block definition to another.

Remove a Block Definition

The block definition remains in the drawing, even when all references to that block are erased. In order to remove the block definition, you need to purge it.

Modify the Data in Block Attributes

You can edit the values of attributes that are attached to a block and inserted in a drawing.

You can use any of the following methods to edit the values of attributes attached to a block:

  • Double-click the block to display the Enhanced Attribute Editor
  • Press Ctrl and double-click the attribute to display the in-place editor(If you press Ctrl and double-click an attribute that includes a hyperlink, the hyperlink opens the web page. To edit the attribute, use one of the other methods listed.)
  • Open the Properties palette and select the block

You can also change the location of attributes in a block using grips. With multiple-line attributes, you can also move grips to resize the width of the text.

Modify Attribute Definitions With the Block Attribute Manager

You can modify attributes in block definitions with the Block Attribute Manager. For example, you can do the following:

  • Modify tags, prompts, and default values. These changes do not affect the values entered when existing block references were inserted. For example, if you change an attribute tag from “Cost” to “Unit Cost,” a value entered at the prompt (such as 19.99) is unaffected.
  • Reset the attribute modes. Modes control tag visibility, whether the value is a constant or a variable, the use of multiple-line text, the verification requirement, and position locking.
  • Change the attribute text display. You can modify alignment, style, height, rotation, width (for multiple-line text), and whether it uses annotative scaling.
  • Set properties that define the layer, color, lineweight, and linetype of the attribute.
  • Change the order of display for attribute prompts. The order in which you select the attributes when you define a block determines the order in which you are prompted for attribute values when you insert the block reference. You can change the order of prompts that request attribute values.
  • Identify duplicate tag names. Because duplicate tag names can lead to unpredictable results, you can set the Block Attribute Manager to highlight duplicate tags so that you can change them.
  • Remove attributes. You can remove attributes from block definitions and from all existing block references in the current drawing. You cannot remove all attributes from a block; at least one attribute must remain. If you need to remove all attributes, redefine the block.

If constant attributes or nested attributed blocks are affected by your changes, use REGEN to update the display of those blocks in the drawing area.

Modify a Block Reference

You can modify the position, scale, rotation, and other properties of a block reference in the Properties palette. These changes affect only that instance of the block reference, not the block definition.

Explode a Block Reference

If you need to modify one or more objects within a block separately, you can disassemble, or explode, the block reference into its component objects.

After the block is exploded, you can

  • Create a new block definition
  • Redefine the existing block definition
  • Leave the component objects uncombined for other uses

The exploded block reference is disassembled into its component objects; however, the original block definition still exists in the drawing for insertion later.

Note: You can automatically explode block references as you insert them by selecting the Explode option in the Insert dialog box.

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