number of bones

Hello

It is well known that fps depend on the number of tris of the mesh.
I wonder wether also the number of bones may have a significant influence on the fps.
Also ,is it true that vertex animation (.md2) is much faster than skeleton animation(.b3d)?

Yes and yes. The number of bones has a significant effect, because vertex positions have to be recalculated accordingly. MD2 is faster because the positions are precalculated. I don't recommend MD2 for anything more than very small, very low poly characters though. Otherwise, it's better to try to optimize your skeletal animation if you can.