The analytical method of chlorogenic acid in sunflower cake by thin-layer chromatography(TLC) was developed. With 36% acetic acid as mobile phase and on the polyamide film plate, the Rf value of chlorogenic acid was 0.61. The calibration curve was linear in the range of 0.05 microgram-0.6 microgram of chlorogenic acid with the detection limit of 0.025 microgram and the average recovery of 97.53%. The inter-plate accuracy of chlorogenic acid was 2.57%. With 70% ethyl alcohol as extracting solvent and 30 min of extraction time, the amount of chlorogenic acid in the extract, the residue amount of chlorogenic acid in the sunflower cake and the extraction rate were determined and calculated by applying this method. The optimal time of extraction was found.