Objective The methods for determination of Chlorogenic Acid(CA) in Eucommia ulmodies Oliv were established and determinated the content of CA. Extract solvent, method, time and times were studied and HPLC method for determination was used. Methods The HPLC system consisted of the column of Lichrospher C18 (4.6 mm?250 mm, 5 ?m) and acetonitrtle-water-phosphoric acid (13∶86.5∶ 0.5) as the mobile phase. The temperature was 25℃. The detective wavelength was 327nm. The flow rate was 0.8 mL/min. External standard method was used. Results The powder of eucommia was extracted twice with 60%methanol-water solution at 100 ℃, the first time for 1.5 h,the second for 0.5 h was the optimum one. The method was linear within the range of 2.22?10-2～55.40?10-2 ?g, the average recovery was 99.55%, and the RSD was 1.98% (n =6). Conclusion The method is simple, sensitive and highly reproductive, and it is suitable for ananlysis of CA in Eucommia ulmodies Oliv.