In this paper we suggest that in order to analyse the proper- ties of an AspectJ aspect one can consider the aspect itself and the part of the system it affects. In fact, we argue that in AspectJ every pointcut declaration defines a “slicing cri- terion” that can be used to compute the associated slice. One can use the sliced programme to build useful models of the system and the aspects and exploit them to prove properties. For example, non-interference at code level can be guaranteed if the slices associated to different aspects are disjoint.