The optimum conditions of chromatograph separation were selected for the ginkgolides BB,GA,GJ,GB and GC. Selecting squalane (SQ) as an internal standard, the weight correction factors of ginkgolides were confirmed by measurement and theoretical calculation. The contents of the five ginkgolides were determinated by internal standard method. The average recoveries of the method for BB,GA,GB and GC were 92.8%,93.2%,92.4% and 94.4%, RSD were 2.9%,1.6%,2.2%,1.9% and 1.9% respectively.