Abstract: As we all know,dynamic slicing technique is very useful in understanding,analysis and verification in the domain of sequential transformational programs．The classical definition of dynamic slicing is not suitable for Statechart specifications．We firstly formally defined a formal semantics model－observable semantics,which only describes outside observable behavior and conceals unobservable behavior of Statechart specifications,so it is very suitable for dynamic slicing．Then we proposed a new notion of dynamic slicing that is more natural for Statechart specifications．We formally defined notions of dynamic slicing criterion,dynamic slice generation algorithm and minimal dynamic slice.We also explained how to produce valid dynamic slicing criterion and proposed a simple and practical approximation algorithm for minimal dynamic slice generation using observable semantics as an intermediate representation.

Key words: Statechart specification,Dynamic slicing,Slice criterion,Observable semantics