Abstract: The effects of medium compositions and culture conditions in Monascus liquid culture were studied on the production and the ratio of Monacolin K and Lovastatin.The optimal temperature-shift cultivation was 2days culture at 30℃followed with 7days at 26℃to increase the production of acid form Monacolin K.By this culture conditions, the proportion of acid form Monacolin K in total Monascus products reached to 87% and it was 2.63times of the ratio produced with constant temperature cultivation at 26℃.Comparing with basic culture medium, additional 8% xylose, 3% peptone, 0.2% NaNO3, 0.2% KH2PO4and 0.35% MgSO4added into the basic medium was the optimal composition that produced the highest amount of Lovastatin compounds with the culture conditions in 6%inoculums size, 160rmin-1 rotate speed at the optimal temperature-shift cultivation.The ratio of acid form Monacolin K was 18times of it produced by the basic medium.