Abstract:The protein components of five immature broad bean varieties in three edible stages were analyzed to explore the changes of protein components of immature broad bean seeds.The components of albumin，globulin，gliadin and gluten were extracted by fractional extraction，and their contents and components were determined by Coomassie brilliant blue method and sodium dodecyl sulfate polyacrylamide gel electrophoresis（SDSPAGE）.The results showed that the most important protein components of five broad bean varieties were gluten，followed by albumin and globulin，and the content of gliadin was the lowest.With continuous ripening of broad bean seed，the content of albumin and globulin increased obviously，the gliadin decreased obviously，and the content of gluten varied with varieties respectively.At the same edible stage，the protein content of different varieties had differences.With the delay of the edible stage，the SDS-PAGE bands of albumin and globulin increased gradually.As the broad bean seeds matures，the protein content of each component changes：from S1 to S2 stage，albumin 40 kDa strip became shallow，add 15 to 35 kDa stripe newly，globulin 40 kDa became shallow or even disappear，add 20 kDa to 35 kDa and 55 kDa stripe newly.From S2 to S3 stage，the 15 kDa to 35 kDa small molecular weight bands of albumin were shallow and their content was reduced，and appeared the 60 kDa-65 kDa and 70 kDa-85 kDa bands，even more larger molecular weights.The 15 kDa to 35 kDa small molecular weight bands of globulin were shallow and 40 kDa stripe again and deepening，and appeared the 60 kDa-65 kDa and 70 kDa-85 kDa bands，even more larger molecular weights.These suggested that some proteins were degraded to a certain stage，some of the new protein had been synthesized.