The present invention discloses a quinoline compound represented by the formula A or pharmaceutically acceptable solvate, optical isomer or polymorph thereof, wherein X is S or O; M is H, Na+, NH4+ or Ca2+; each of R1, R2 and R3 is independently H, halogen, the group represented by formula D or formula E; R is H, halogen, C1˜C4 alkyl or C1˜C4 alkoxy. The present invention also discloses its pharmaceutical composition and the preparation method thereof and application in manufacturing a medicament for inhibiting HMG-CoA reductase or for the treatment and prophylaxis of the diseases which can be treated effectively by inhibiting HMG-CoA reductase. The quinloline compound and pharmaceutical composition thereof of the present invention have an excellent lipid reduction effect in vivo and can be applied for treatment of a hyperlipidemia-related disease.