This is part of the ADT/SDK update and it is not a bad thing to happen. It ensures that your app has full support of the ActionBarActivity that was implemented in API 14+. It will get created each time by default, but with a little work you can keep your files down. I simply have a single appcompat_v7, whenever I create a project, let's call it SampleApplication, appcompat_v7_2 is created.
- How to re-reference your library - Right click on "SampleApplication" Go to "Properties" Click "Android" Scroll to the bottom's "Library" section Click "..\appcompat_v7" Click "Remove" Click "Add" Click on "appcompat_v7" Click "Apply"
Now you have referenced your preexisting library. You now need to delete your old "extra" duplicate appcompat_v7_2 library. I do this as follows:
- Deleting duplicated copy - Right click on "appcompat_v7_2" in the Package Explorer of your workspace Click "Delete" Go to your physical workspace (In Windows, something like C:\...\...\workspace) Find "appcompat_v7_2" Right click on "appcompat_v7_2" in your physical workspace Click "Delete" Restart Eclipse
It is not ideal as it requires a bit of setup for each application. But it works. You can also uncheck "Create Activity" when you are creating your application project and it won't add the library (but also, obviously, won't include your main activity).
As another note, apparently for some people it doesn't include the library if your minimum sdk version for your application is 11+. For me, however, it always includes it, so this is my way around it
i got this from this link he explained very good, it might seem same as your question check there
https://stackoverflow.com/questions/22542978/remove-v7-appcompat-folder

This is a duplicate-
I have answered this here https://stackoverflow.com/questions/22542978/remove-v7-appcompat-folder/22543448#22543448 but will include it here as well
This is part of the ADT/SDK update and it is not a bad thing to happen. It ensures that your app has full support of the ActionBarActivity that was implemented in API 14+. It will get created each time by default, but with a little work you can keep your files down. I simply have a single appcompat_v7, whenever I create a project, let's call it SampleApplication, appcompat_v7_2 is created.
` - How to re-reference your library - Right click on "SampleApplication" Go to "Properties" Click "Android" Scroll to the bottom's "Library" section Click "..\appcompat_v7" Click "Remove" Click "Add" Click on "appcompat_v7" Click "Apply"`
Now you have referenced your preexisting library. You now need to delete your old "extra" duplicate appcompat_v7_2 library. I do this as follows:

`- Deleting duplicated copy - Right click on "appcompat_v7_2" in the Package Explorer of your workspace Click "Delete" Go to your physical workspace (In Windows, something like C:\...\...\workspace) Find "appcompat_v7_2" Right click on "appcompat_v7_2" in your physical workspace Click "Delete" Restart Eclipse`

It is not ideal as it requires a bit of setup for each application. But it works. You can also uncheck "Create Activity" when you are creating your application project and it won't add the library (but also, obviously, won't include your main activity).
As another note, apparently for some people it doesn't include the library if your minimum sdk version for your application is 11+. For me, however, it always includes it, so this is my way around it.