Objective To investigate the characteristic of OCT images of congenital macular coloboma and its utility in the diagnosis of the diseases. Methods Seven patients (9 eyes) with congenital macular coloboma who had been examined by visual acuity determination, slit lamp examination, ophthalmoscope and fluorescein angiography received OCT scan and fundus color photography. The results were retrospectively analyzed. Results The manifestation of congenital macular coloboma by OCT was the retinal and choroidal tissues focally pitted outwards along with sclera. The 3 dimensions of pit: horizontal diameter 668- 4 339 ?m ( 3 119 in average), vertical length 668- 4 531 ?m ( 2 591 in average), pits depth 230-2 146?m(1 084 in average).The retinal neurosensory layer became thin and defect. And the retinal neurosensory layer was thinner in the centre than that near the edge. Reflection of retinal pigment epithelium was uneven and discontinued. The dark area of choroid was enlarged. Conclusions It can be clearly shown by OCT that abnormal structure of retina and out layer of choroid in congenital macular coloboma. It is implied that the characteristic of OCT is helpful in the diagnosis of congenital macular coloboma.