Objective: Sulfur mustard or HD, is one of the first chemical warfare agents to be used widely during World War I and Iran-Iraq war. Sulfur mustard is a potent nucleophile, readily penetrating the skin, mucus membranes and the eyes, that alkylates cellular components and causes cytotoxicity and the release of inflammatory mediators from insulted cells, thus initiating an inflammatory response. The meibomian glands in eyelid are one the most sensitive organ of eye to sulfur mustard (HD) exposure. Anti-inflammatory treatments might have the potential to prevent some aspects of the primary development of HD-induced lesions. As opposed to the alkylating events that occur within the first minutes after exposure, the release of inflammatory mediators after HD exposure is slower. Therefore, any treatment that intervenes with this inflammatory process may ameliorate the clinical symptoms. The aim of the present study was to characterize further the inflammatory aspects of Histology, histomorpholoy of acute HD lesions and to evaluate the therapeutic and protective effects of Betamethasone and Diclofenac-Na on meibomian glands lesions following HD exposure Materials and Methods: In the present experimental work 36 rabbits were used. Animals were randomly divided into three control groups and three experimental groups. In each group six animals were examined. Right eyelid of all animals was selected for experiment. Control groups included Normal (N), Solution (S) and HD group. Prophylaxis groups included Betamethasone (B), Diclofenac-Na (D) and Betamethasone+Diclofenac-Na (BD) were applied after expose to HD solution. Application of drugs was performed 3 times a day, for 2 weeks. Animals were sacrificed in the end of 14th day of studying with ether. Para sagital sections have prapared from rabbit’s eyelid. The sections were studied from aspects of Histology, histomorpholoy. Statistical analysis was performed by t test and ANOVA using Spss software. Data are reported as mean ± SEM at a significance level of p<0.05. Results: There weren’t any significant differences between N and S groups. HD caused malfunction and necroses of meibomian gland. The results showed that all of meibomian glands in experimental groups were better than HD group in terms of histology. B group was more effective than the other groups and decreased significantly meibomian gland injuries. Betamethasone in combination with Diclofenac-Na was low effective than Betamethasone and Diclofenac-Na alone and decreased eyes injuries. Conclusion: Betamethasone and Diclofenac-Na are potential candidates for prevent the meibomian gland lesions following HD exposure.