Abstract: The volatile components and differences of instant soybean powder,milk powder and goat milk powder were identified and analyzed. The results showed that 42 volatile substances were identified in instant soybean powder,48 volatile substances were identified in milk powder,and 47 volatile substances were identified in goat milk powder,including alcohols,aldehydes and ketones,hydrocarbons,acids,esters and other substances. It was found that the types and contents of hydrocarbons,aldehydes and ketones,esters were higher among them.The contents of alcohols and acids detected in instant soybean powder was the highest;the content of hydrocarbons and esters detected in milk powder was the highest;the content of aldehydes and ketones and other substances detected in goat milk powder was the highest. Cluster analysis and principal component analysis results showed that,decanal,(E,E)-3,5-octadien-2-one,1-dodecene,n-decanoic acid,and 2(3H)-furanone,5-butyldihydro-(y13),2-n-pentylfuran,butylated hydroxytoluene were the key volatile substances in instant soybean powder;nonanal,δ-decalactone,dodecane,and 2H-Pyran-2-one,6-heptyltetrahydro-,2,2,4,6,6-pentamethylheptane,1-tridecene were the key volatile substances in milk powder;1-pentanol,heptanal,2-heptanone,dimethyl sulfone,3-octene-2-one,nonanal,and γ-dodecalactone were the key volatile substances in goat milk powder. These substances were the main substances which caused differences in the flavor of instant soybean powder,milk powder and goat milk powder.