I’m OSX version user.
In Tile Animatin Editor, I can’t found a button to remove data and a delete key does not do anything.
What should I do?
Try the ‘Backspace’ key.
WTH! I did it!
I learned for the first time fn + delete = backspace.
I really appreciate it!
Hmm, the shortcut is on the Delete key for me, but I do not have an Apple keyboard connected to the Mac Mini that @TilemapKit once sent me. I guess I should hook it up to Backspace as well.
Could it rather be, that Fn + Backspace = Delete?
Ah, this site cleared it up for me: http://store.apple.com/us/question/answers/mac/are-apple-keyboards-with-only-a-delete-key-less-efficient-in-making-deletions-than-conventional-keyboards-with-both-a-backspace-and-a-delete-key/QA9JYDAJHJHYPYUJF
So Apple keyboards only have a “Delete” key, but it behaves like the “Backspace” key on other keyboards. So when you press “Delete”, Tiled sees a “Backspace”, and that’s not what the action to delete animation frames is bound to. So to make the “Delete” key on the Apple keyboard work in Tiled, I indeed need to bind this action also to “Backspace”.
[insert something nasty about Apple here]
FIY Macbook Pro doesn’t have a Delete key, only Backspace (Fn+Backspace does delete). 
Alright, I’ve pushed a small change that enables Backspace for deletion of animation frames as well, and I did the same for the collision editor, to be included with Tiled 0.12.3:
https://github.com/bjorn/tiled/commit/25bf5d17e13b84ab9e47593c01a2c160637ae394
There’s still some problem preventing the Delete shortcut from working in the main window, but right now I have no idea about what is causing that problem so I’ll leave that for later.