Upper: Synthetic
Lining: Synthetic
Sole: Synthetic
This is our 3rd pair of this design. My daughter loves them so much we just buy the next size up.
The touch velcro is very handy, but as with any velcro used 2-3 times a day the grip does lessen considerably after a few terms of wear. This normally coincided with needing the next size up, so not a big problem.