As the most important component of pervasive computing in mobile business, context-aware system gets more and more attention from the researchers. One of the basic technologies used to implement the contexts' description and reasoning in context-aware systems is ontology which has the big advantage at knowledge presenting and sharing. However, the shortage of the existing methods with ontology is obvious that most of them are predefined which makes them too fixed to provide the flexible services. In this paper, we provide CS_SRM, a totally new method to provide the flexible service recommendations based on the similarity computing of the semantic meanings in the given concepts which are corresponding to the different contexts. At last the simulating experiments prove its effectiveness.