Cloud Software as a Service (SaaS) is a type of delivering software application by using Cloud computing Infrastructure services. Cloud SaaS used the global Internet connection to offer its services to the client consumers. The selection of Cloud SaaS provider is based on the evaluation mechanism that the Cloud SaaS consumer manage before making the service contract. In this paper, the linguistic-based evaluation of Cloud SaaS quality attributes has been proposed to help the consumer to assess the service for optimal service selection. Our proposed approach has been developed by the combinations of fuzzy logic and TOPSIS MCDM methods. The proposed approach helps the Cloud SaaS consumer to select the optimal service Cloud SaaS service provider. The case study has been proposed in order to demonstrate the proposed approach.