Abstract: Objective The 3-hydroxy-3-methylglutaryl-coenzyme A synthase and reductase (HMGS and HMGR) were analyzed by their dynamics and function; Methods The genes of HMGS and HMGR were cloned from S.pneumoniae and expressed. Their inhibition effect was tested by lovastatin and the candidate inhibitors; Results Lovastatin can inhibit HMGS, but not do for HMGR. It is more effective in the virtual screening with the reacting product catalyzed by HMGS instead of 3-hydroxy-3-methylglutaryl-coenzyme A（HMG-CoA）; Conclusions Lovastatin is a kind of competing inhibitor targeted for HMGR. The product can be used to screen preliminarily plentiful candidate inhibitors and develop new inhibitors with more specific and stronger function.

Key words: Streptococcus pneumoniae, HMG-CoA synthase, HMG-CoA reductase, Kinetic characteristics, Function