if a is an abelian variety over a p-adic field k then a has good reduction if and only if the p-adic tate module of a is a crystalline representation of the absolute galois group of k. as there are examples of curves over k with bad reduction whose jacobian has good reduction, the galois action on the p-adic etale cohomology of the curve does not determine its reduction. we will discuss these issues and point to a p-adic criterion of good reduction for curves.