An evaluation of knowledge management system was studied.Firstly,according to the capability,function,circumstance,cost and human factor of knowledge management system,the factors of evaluation for knowledge management system were analyzed.Then,on the basis of these factors,an index system involving the capability,function,circumstance,and cost of the system and human factor were established.Next,an integrated evaluation method for the knowledge management systems based on linguistic symbol operators was presented.Finally,an example was given to illustrate the application of the proposed method.