PURPOSE:To evaluate the ability Of retinoic acid(RA) in silicon oil(SiO)to inhibit the proliferation of injected intraocular fibroblast cells. METHODS:Thirty New Zealand white rabbits (58 eyes)were divided into three groups. In control group ,only SiO(10 eyes)or BSS(10 eyes)were injected intravitreally and 5mu;g/ml (18 eyes)or 10mu;g/ml (20 eyes)RA in SiO were injected into other lwo groups respectively. Three days after gas-compression vitrectomy, 2 times;105 fibroblasts and Sio(0.5ml)or BSS(0.5ml)were injected in all eyes sequentially.The morbidity of tractional retinal detachment (TRD) were observed by ophthalmoscope until 4 weeks. RESULTS:After 4 weeks,in control ,5mu;g/ml RA in SiO and 10mu;g/ml RA in SiO group,80. 00%,44.44%,and 30.00% eyes developed TRD respectively. Significant statistical differences were found between the control group and the two treated groups (P＜0.05). CONCLUSIONS:5mu;g/ml or 10mu;g/ml RA in SiO can inhibit the occurrence of TRD effectively. （Chin J Ocul Fundus Dis,1997,13:174-176）