Abstract: Study by flaxseed, create the HPLC method of analysis α-linolenic acid content in flaxseed. External standard quantitative analysis, the linear ranger of α-linolenic acid was 33.04- 495.6μg / mL, the standard curve R2 is between 0.9995 to 0.9999, and the average recovery is 99.6%with RSD 2.66% （n=6）. The sensitivity and the accuracy were all satisfy the requirements of quantitative analysis.