The increasing use of Web services as well as the growing interest lent to Cloud computing technology and its capacity of calculation, storage and Cloud services, impose today that the traditional mechanisms of discovery must be reexamined. This specificity of discovery over the cloud led us to propose a new framework based on mobile agents dedicated to web services discovery. So the problematic, consist of making this framework, benefiting from the characteristics of Cloud computing and mobile agents technologies. More accurately, we propose a new algorithm of comparison between the request of the client and the description of the Web services. The proposed system is composed of two areas of Cloud. The first deals with Key words based research and second supports the filtering of the found web services. This discovery is performed by an algorithm based on the calculation of similarities between the request and the description of the web services. The results show that the quality of the service (response time) has been enhanced due to the proposed virtualization policy, which consist of decomposing the discovery operation to six main tasks then creating, for each task, its own virtual machine (VM), each time we create a new VM the response time is reduced.