Purpose: To evaluate the clinical efficacy of FK-506 on suppressing high-risk cornea transplantation rejection.Methods: In a randomized controlled clinical trial, 56 eyes of 56 patients with high-risk keratoplasty (including total corneal transplantation TCT, total corneal transplantation with circular lamellar sclera CST, vascularization corneal transplantation and corneal retransplantation) were divided into the experimental group and the control group (each with 28 eyes). The experimental group was treated by FK-506 eyedrops (0. 5 mg/ml) and TobraDex eyedrops, compared with the control group that was treated by 1% CsA eyedrops and TobraDex eyedrops. In the average 8. 1-month follow-up period, the visual acuity, graft transparent duration and Rejection Index (RI) of grafts were observed. Results: In the follow-up period, the graft rejection rate of the experimental and the control group was 63. 6% and 95. 2% respectively (x2 =4. 72, P<0. 05) with significant difference.Conclusions: The local applicati Purpose: To evaluate the clinical efficacy of FK-506 on suppressing high-risk cornea transplantation rejection. Methods: In a randomized controlled clinical trial, 56 eyes of 56 patients with high-risk keratoplasty (including total corneal transplantation TCT, total corneal transplantation with circular lamellar sclera CST, vascularization corneal transplantation and corneal retransplantation were divided into the experimental group and the control group (each with 28 eyes). The experimental group was treated by FK-506 eyedrops (0.5 mg / ml) and TobraDex eyedrops , compared with the control group that was treated by 1% CsA eyedrops and TobraDex eyedrops. In the average 8. 1-month follow-up period, the visual acuity, graft transparent duration and Rejection Index (RI) of grafts were observed. : In the follow-up period, the graft rejection rate of the experimental and the control group was 63. 6% and 95. 2% respectively (x2 = 4.72, P <0.05) with significant difference. Conclusions: T he local applicati