In this study,with the addition of different proportion(0,4% and 10% m/m) of fresh goat milk and Soy protein isolate(SPI),high concentration direct-set lactic bacterial including Lactococcus lactis and Leuconostoc,and Propionibacterium freudenreichii ssp.Shermanii were used as the raw material,main culture and secondary culture,respectively,to make goat milk and SPI mixed cheese.Volatile compounds of the cheese were enriched by solid-phase microextraction(SPME) and determined by GC/MS after the cheese maturation.The influence of SPI to volatile compounds of cheese was studied and the appropriate ratio of SPI addition was determined.The result indicated that the major volatile compounds of cheese were acid compounds,following the ketone,alcohol,aldehyde,and ester compounds.SPI addition reduced the contents of acid and ketone compounds of cheese significantly and increased the contents of alcohol compounds.The complexity of the cheese flavor was enhanced when SPI addition was 4%,with a rich cream,butter aroma and less special flavor of goat milk,phenol and pyrrole compounds appeared as well.