Sorry that the Animatino library I post before isn't support XNA2.0. I should read more carefully next time><"
However, I find a new one which called "XNAnimation" support XNA2.0
I have tested it with my character class and it work. I import its demo model and it can really "run" on the floor with animation.The library supports cross fade between animation clips and keyframe interpolation.
But there is a problem that the library have 2 version
For version 1, it support PS2_0A (pixel shader) . It is better than PS2_0 but it doesn't support for our fyp computer which only support PS2_0.
For version 2, it updated a little bit. It support PS2_0 but some method are disabled
And it seems that if we change the library version or computers during development, the model will have some bad changes. I will do some more tests to confirm whether it's a problem or not.