Abstract: To establish a rapid qualitative and quantitative detection model of cottonseed oil adulterated into rice bran oil ( RBO) , unadulterated RBO and adulterated RBO with different proportion cottonseed oil were detected by capillary gas chromatography.Contents of C10∶0, C14∶0, C16 ∶0, C16 ∶1, C17 ∶ 0, C18 ∶ 0, C18 ∶ 1, C18 ∶ 2, C18 ∶ 3, C20 ∶ 0, C20∶1, C22∶ 1 were made as variables. Qualitative detection was made by using cluster analysis and discriminant analysis.Result: Cluster analysis was able to made correct identify when RBO mixing cottonseed oil by more than5% and discriminant analysis more than 20%. Quantitative detection models YC14∶0= 0.004 X + 0.3168 ( R2= 0.9813) based on characteristic fatty acids and Y =-240.52X5+ 677.8X4-697.92X3+ 312.09X2-66.998 X + 99.97 ( R2= 0.9993) based on fingerprint similarity were built.The model had good repeatability, high accuracy with error less than 5%.