How come when i jump rope the arches of my feet get sore after a couple minutes?

Likely: They need support. Wear an orthotic or arch support when performing this excercise next time.

Lack of support: If you have a flexible arch or flat foot position or old and worn out shoes, this will cause excessive movement in the middle arch area of your feet that will cause ligament movement to the joints and bones and create teh sore arches. Try either taping your feet or getting a more stable shoe. Avoid a very flexible shoe and don't jump barefoot.