I guess it's a fantasy movie in the 80's, all I can remember is this blonde girl riding a horse and all of a sudden a bunch of scary warriors attack the girl and she falls off her horse.

I saw that no one responded to your question so I though I would take a shot...
It may be.. The Battle for Endor (1985)
There is a little blonde girl that gets kidnapped on a horse and these scary creatures do chase her in the forest. I don't know if this is the one you are looking for. It is part of The Ewok Adventures.

Hope I helped.