Objective　To investigate, compare and filtrate the collagenase inhibitor effects among six kinds of eye drops for clinical use.Methods　The collagenase inhibitor’s effects were detected by rat's collagen and collagenase with comassie brilliant blue colorimetric method.Results　The inhibitting collagenase effects among six kinds of eye drops were different: the effect of cartopril was the strongest；the acetylcysteine and sodium edetate were more strong and the sodium citrate, sodium hyposulfite and tetracycline were less strong.Conclusion　 0.5g*L-1cartopril eye drops has stronger efficacy to inhibit collagenase, with less side effect or stimulation，more convenient resource and preparation than other eye drops.