Abstract: With orthogonal experiments，the extraction process was optimized，and by RP-HPLC，the detection method was established for ginsenosides from Panax japonicus root in Guizhou. The results showed that the optimal extraction process of ginsenosides from P. japonicus root was as follows：ratio of material to liquid with 1∶10，methanol concentration of 65%，at 50℃. At the wavelength of 203 nm，the linear regression equation of Re，Rg1，Rg2，Rh1 and Rh2 were y=42.08+24.25x，y=52.23+43.87x，y=40.09+3.51x，y=115.36+32.41x，y=98.46+30.52x，respectively， the linear range and correlation coefficient were 0.18-15.45 μg and 0.996-0.998，indicating that the method had good reproducibility，stability，high precision and sample recovery rate. The content of ginsenosides monomer increased with the growth period of P. japonicus increasing. Except for Rg2，the contents of other four kinds of ginsenosides monomer were more than 1 mg/g in five-year P. japonicus root. At different growth period of the same year，the content of Re was higher than that of the other four，indicating that Re was the main ginsenoside from P. japonicus root in Guizhou