The need for adaptability in software is growing, driven in part by the emergence of autonomic computing. In many cases, it is desirable to enhance existing programs with adaptive behavior, enabling them to execute effectively in dynamic environments. The peer-to-peer (p2p) paradigm is attracting increasing attention from both the research community and software engineers, due to potential performance, reliability and scalability improvements. P2P model has opened many new avenues for research and applications within the field of distributed computation, so performance evaluation is unavoidable.Existing web service invocation and adaptation mechanisms are limited only to the scope of web service choreography in terms of web service selection. Such a scope hardly leaves ground for a participating service in a choreographed flow to re-adjust itself in terms of changed non functional expectations.In this paper we are using Aspect oriented programming (AOP) to enable dynamic adaptation at the time of invoking web services in P2P Systems. We propose an approach to implement dynamic adaptability especially in existing p2p JXTA-WS programs and Aspect weaving in p2p JXTA Multicast sockets using AOP. We have used AspectJ; Java based language to create aspects in Eclipse supported framework.