Abstract： Objective To investigate the inhibitive effect of hematoxylin A on the rejection of corneal allograft in rats following corneal transplantation.Methods Twenty SD rats were used as donors and another 40 Wistar rats were used as receivers,and the SD-Wistar rat model of allogeneic penetrating keratoplasty was established.The animals were randomly divided into 4 groups:i.e.group A treated with artificial tear (or the control group) ; group B treated with 0.1％ prednisolone eye drops (or the 0.1％ prednisolone group) ; group C treated with 0.5％ Hematoxylin A eye drops (or the Hematoxylin A group) and group D treated with 0.1％ prednisolone eye drops plus 0.5％ Hematoxylin A eye drops (or the combined treatment group).Following surgery,rejection index (RI) and survival time of corneal grafts were compared between patients of different groups,and observations were made on the survived grafts by immunofluorescence staining.Results Slit lamp observation of corneal grafts indicated that group A had obvious rejection reaction,followed by group B and C,and group D showed the slightest reaction.The survival time of corneal grafts for group A,B,C and D were (8.00 ± 0.58),(15.80 ± 0.36),(15.20 ± 0.49) and(23.40 ± 0.43) days respectively.Statistical significance could be noted,when group A was compared with group B,C,and D,and statistical difference could also be found,when group D was compared with group B and C (P ＜0.01).Ten,twenty and thirty days after corneal transplantation,corneal graft rejection indexes of group B,C and D were all significantly lower than that of group A,with statistical significance (P ＜ 0.01).Corneal graft rejection index of group D was significantly lower than those of group B and C,also with statistical significance (P ＜ 0.01).No statistical difference could be seen in corneal graft rejection indexes,when comparisons were made between group B and C (P ＜ 0.01).Results of immunofluorescence staining indicated that the levels of IL-2 in corneal grafts for group A,B,Cand D were respectively(15.91 ±0.14),(8.19 ±0.07),(7.96±0.08)and(5.81 ±0.11).Statistical difference could also be noticed,when group B,C and D were compared with group A,and the same results could be obtained,when group D was compared with group B and C,all with statistical significance (P ＜ 0.01).However,no statistical significance could be seen,when comparisons were made between group B and C (P ＞ 0.05).Conclusions Hematoxylin A could produce certain inhibitive effect on corneal graft rejection,its effect was similar to that of prednisolone,and seemed to have a synergistic effect with prednisolone,the mechanism of which might be associated with the inhibition of IL-2 expression.