The phenomenon of protein aggregation during the production of a bio therapeutic drug is an increasing challenge to many pharmaceutical research and development groups and companies.Aggregation may cause a number of deleterious effects on protein drugs,including the loss of efficacy,the induction of immunogenicity,alteration of pharmacokinetics and reduction of shelf life.Size exclusion chromatography(SEC) is a traditional technique widely employed for the qualitative and quantitative evaluation on pharmaceutical proteins and their aggregates,which possesses some advantages such as easy operation,mild mobile phase conditions and nondestructive detection of the conformational structure and local environment,etc.However,SEC method still remains a number of limitations,in which the most important one is the adsorption of protein to resin.The theory for SEC separation is outlined in this review,and some methods how to reduce the nonspecific adsorption problem are described.Some techniques mutually comlementary with SEC are listed, which could be used in the analysis on pharmaceutical protein aggregates.Finally,the future development and outlook for SEC technique are described.