AIM:To probe into a method of rapid diagnosis of acanthamoeba keratitis with polymerase chain reaction(PCR).METHODS:PCR was performed to detect the DNA segment of acanthamoeba from standard strain and applied to 24 scraping samples from patients’ cornea.The results were compared with protozoan culture and 100g/L KOH wet mount.RESULTS:We successfully detected acanthamoeba from standard strain and samples from patients’ cornea 5 hours after PCR,but not from bacteria,fungi,herpes simplex virusⅠ(HSV-Ⅰ)and human corneal cells.The positive rate of samples from patients was 46%,which was higher than protozoan culture or 100g/L KOH wet mount(P<0.05).CONCLUSION:PCR is fairly valuable to get rapid and definite diagnosis of acanthamoeba keratitis.