Abstract: Residual organic solvents methanol,alcohol,acetone,dichloromethane, ethylacetate in Lansoprazole were determined by capillary gas chromatography using a OV-101 capillary column (0.22 mm×30 m).DMF was used as the solvent.Butanone was adopted as internal standard.Nitrogen gas was used as carrier.The front pressure of column was 56 kPa.The column temperature is programmed according to the following steps: it is held at 35 ℃ for 4 minutes then raised to 150 ℃ at a rate of 20 ℃ per minute,and it is retained for 10 minutes at 150 ℃.Methanol,alcohol,acetone,dichloromethane,ethylacetate were well separated in the column with the mean recovery of 100.8%±3.6%,102.1%±2.3%,99.97%±4.1%,99.63%±2.7%,102.3%±3.5% and their detection limits were determined as 0.002 4%,0.002 4%,0.001 2%,0.000 6%,0.000 6% respectively.The standard curves were linear in the concentration range of 10-1 000 μg·L-1 (r=0.999).