Sound like Peach leaf curl. This is a nasty fungal infection which is very hard to control. You must pick off and burn any affected leaves and spray the tree with a systemic fungicide. Sadly even then there is a large chance that it will return as once it is in the soil/area then there is not much one can do about it. We had to get rid of ours in the end.

thanks i will take your advice.bigalfie