With the evolution of new software technologies, the requirements for automated testing are becoming more and more stringent. With increasing size of software projects, manual testing is becoming less efficient. For automated testing one of the most important question is, what to focus upon while testing? For a large number of functions along with large number of possible call sequences, it is very hard to generate test cases that cover all possible paths of control flow. By finding patterns in the calling sequences we will be able to identify more defects by focusing our testing efforts on those patterns. In this paper, we have described our work on tracing call sequences using Aspect Oriented Programming methodology and discovering those patterns in call sequences using data mining techniques.