Abstract: Based on the body measurement database,sales database data mining,decision methods concerning specifications,size and proportion for costume commission were researched.It used the data mining K-Means method to characterize patronage body sizes of the databases,guide and simplify the specification table of regional apparel products.Clustering use of SubCluster method for refining regionalization clothing body measure data,as guiding production of ″regionalization specifications and type″ of the crowd;It was very useful to classify specifications from human groups in some regions,and it can be used reliably for getting specifications table in mass custom-made.And then,based on type and specifications ratio decision model with statistics and data mining method form sales specifications database and body size database and inventory database,the foundation of the project of ″Based on 3-D Size-Type Clothing Decision Making System Development″ was established,and practical software was also developed for it.