AlM：To investigate the related factors of effects on best-corrected visual acuity (BCVA) after intravitreal Avastin combined with macular grid photocoagulation(MGP) for diabetic macular edema(DME). METHODS：A retrospective review of a consecutive series of 41 DME patients(41 eyes) who received intravitreal Avastin combined with MGP. Gender, disease course, the changes of central macular thickness (CMT), type of DEM, changes of postoperative CMT, massive subfoveal hard exudates and visual acuity 1 month after treatment were recorded. Multi-factor regression analysis of BCVA after the combined treatment was performed with SPSS statistics software. P<0.05 was considered statistically significant.  RESULTS: The postoperative BCVA was related to the preoperative BCVA, disease course, the changes of CMT and massive subfoveal hard exudates (P<0.05). CONCLUSlON: The better preoperative BCVA is, the better postoperative BCVA would be. Early treatment for the patients with DME would get better postoperative BCVA. Postoperative BCVA is relatively improved in patients with obvious regression of macular edema. Patients with massive submacular hard exudates could hardly be improved in postoperative BCVA.