Objective To diagnose limb-girdle muscular dystrophy type 2A(LGMD2A)using Western blot with micro-sample.nethods Skeletal muscle specimens of 73 cases of progressive muscular dystrophy with prominent proximal muscle involvement were obtained by open biopsy,and underwent histochemical,immunohistochemical stains with anti-dystrophin-N,C,R,α,β,γ,δ-sarcoglycan,dysferlin,caveolin-3 monoclonal antibodies.Twenty-nine cases were excluded with deficiency of dystrophin,sarcoglycans,dysferlin and caveolin-3,then Western blot and immunoreaction were performed with anti-calpain-3,caveolin-3 monoclonal antibodies.Results Ten cases with LGMD2A were diagnosed,all presenting muscle weakness of the proximal limb and elevated creatine kinase in vacant levels.and electromyography showed myogenic change.Histochemical stains showed variation in fiber size,different extent of degeneration,regeneration and necrosis,increased connective tissue elements,while lobulated fibers presented in 6 cases.Immunohistochemical stains identified dystrophin,sarcoglycans,dysferlin and caveolin-3 expressed normal in muscle fibers.Western blot,compared with the control,confirmed that the bands at 94 000 were absent(8 cases)or partly(2 cases)deficient:The additional bands at 30 000expressed weakly;The bands at 22 000 were normal.Conclusion Western blot analysis with microspecimen of skeletal muscle is an effective modality to diagnose LGMD2A,and is suitable to diagnose the sub-type of LGMD in clinic.