AIM: To analyze the reasons that may lead to the different vision result by combining the ranibizumab and triamcinolone acetate (TA) in sequence to treat macular edema in retinal vein occlusion (RVO). METHODS: Ranibizumab and TA were combined in sequence to treat 43 patients with macular edema secondary to RVO. Six months after the treatment, patients with central fovea thickness (CFT) less than 300 μm in optical coherence tomography (OCT) were collected into GroupsⅠand Ⅱ, based on vision acuity (VA) better than 78 letters or less than 60 letters. The age, baseline VA, duration from onset to treatment, CFT at the baseline, sub-retinal fluid (SRF), sub-foveal exudates and injection times of TA and ranibizumab were taken into comparison. RESULTS: The mean age of the subjects was 46.4y in Group Ⅰbut 57.5y in Group Ⅱ. The difference of age was significant between groups (P<0.01). The mean baseline VA was 51.4 letters in Group Ⅰand 43.9 letters in Group Ⅱ (P<0.05). The baseline CFT were 670.9 μm in Group Ⅰwith SRF in 54.3% patients and 678.1 μm in Group Ⅱ with SRF in 52.9% (P>0.05). The mean number of injections of TA was 0.9 and the mean number of injections of ranibizumab was 2.3 in Group Ⅰbut 1.7 and 2.9 respectively in Group Ⅱ. The treatment times of ranibizumab had no difference between the 2 groups (P>0.05) but the difference of TA injection times was significant, P<0.05. Subfoveal exudates at final stage happened in no subjects in Group Ⅰ but in 45.83% subjects in Group Ⅱ. CONCLUSION: This combined treatment is safer than TA injection and cheaper than ranibizumab injection alone. Younger patients and earlier treatment will help to get better vision outcome. Subfoveal exudates at the final stage have significant relationship with vision outcome. No relationship existed between the baseline CFT, SRF and the vision outcome.