Static modeling is often difficult to understand when meet with complicated, large-scale Web software which has many unique characteristics. Aim at this problem, this paper proposes a method to create an executable model for Web software based on Live Sequence Charts (LSCs). The executable model can simulate the running of the system, which helps to find the inconsistency of the model in early development stage. Then the LSCs model is transformed to a symbolic automaton. Testing scenarios can be generated by traversing the automaton by depth-first search (DFS). Results showed test cases generated by this executable model are more effective than general model. We hope this method can do some help to the modeling and testing of the Web application.