A new solid phase extraction coupled with high performance liquid chromatography method for quantitatively analyzing two fatty acid tryptamides (FATs), behenic acid tryptamide and lignocerinic acid tryptamide, was established. The cocoa shell content in cocoa powder was calculated according to the differences in FATs contents in the powder and shell. The samples were extracted by trichloromethane with vortex and ultrasonic extraction. The Venusil C₁₈ chromatographic column was used and eluted with acetonitrile/tetrahydrofuran/water,followed by using a fluorescence detector. The results showed that these two FATs showed good linear relationship (r>0.999 1) within their linear range(50-1 000 μg/L). The detection and quantification limits were 0.03 mg/kg and 0.1 mg/kg, respectively. The spike recovery rate was 92%-103% and the RSDs was 2.1%-6.2%. In addition, FATs levels and the cocoa shell contents in cocoa powder samples were processed to establish a simple analysis model. The prediction values had good corresponding relationship with true values. The results showed that cocoa powder adulterated with 5% or more (mass fraction) cocoa shell could be identified by this method.