Polyacrylamide gel electrophoresis was used to separate and determine different proteins and their contents. The result shows that no proteim bands aopeared for amniotic fluid on the 6th day of hatching, 9 bands appeared on the 9th day, and 11 appeared on the 15th d(?)y, (?) which showe(?) the highest protein contents. kinds and their contents varied obviously with time of proteins in c(?)icken embryo amniotic fluid.