Objective To observe the changes of visual acuity and multifocal electroretinogram （mfERG）before and after pars plana vitrectomy (PPV) combined with internal limiting membrane（ILM）peeling with ICG on idiopathic macular hole surgery. Methods The clinical data of 19 patients (19 eyes) with idiopathic macular hole（IMH） who had undergone PPV combined with ILM peeling assisted by 0.25% ICG from Zhongshan Ophthalmic Center were retrospectively analyzed. The closure of macular holes was confirmed by OCT two months after surgery. VERIS Science 4.9 visual evoked response image system was used to record the amplitude density of P1 waves according to six concentric rings before and two,six,twelve months after surgery, meanwhile compared and analyzed best corrected visual acuity（BCVA）before and after surgery. Results The results of OCT showed that 16 eyes (84.21%) had anatomic closure of the macular hole two months after the surgery while three eyes (15.79%) failed in the closure. The BCVA after surgery improved significantly which was more obvious at the second month (F=6.389，Plt;0.05). Compared with before surgery, the responses were depressed severely in P1 wave amplitude densities in six rings, the differences were statistically significant (t=6.140，Plt;0.05). Conclusion The postoperative BCVA of IMH patients improved but the amplitude densities of P1 wave depressed compared with before surgery.