Objective To explore the retinal and choroidal thickness of myopic patients with different diopters, and analyze the change rule and its relation with the diopter. Methods From October 2015 to June 2016, a total of 161 patients (322 eyes) with myopia and 53 normal volunteers (106 eyes) were selected from Department of Ophthalmology, West China Hospital of Sichuan University. Optical coherence tomography (OCT) examination was performed in all the subjects with Macular cube 512×128 and EDI HD-OCT model in Cirrus HD-OCT 5000 of Carl Zeiss Company from Germany, measuring the retinal and choroidal thickness in macular central fovea, and 3 and 6 mm above, below, on the nose side, and on the temporal side of macular central fovea; the data were averaged. According to the different diopters, the subjects were divided into four groups, including emmetropia group with 53 patients (106 eyes), low myopia group (equivalent diopter from –0.25 to –3.00) with 64 patients (128 eyes), moderate myopia group (equivalent diopter from –3.25 to –6.00) with 47 patients (94 eyes), and high myopia group (equivalent diopter <–6.00) with 50 patients (100 eyes). All the subjects’ best corrected visual acuities were ≥0.8. The changes of retinal and choroidal thickness in myopia patients with different diopters were compared and analyzed. Results The average retinal thickness of the patients in the emmetropia group, the low myopia group, the moderate myopia group, and the high myopia group was (242.50±29.86), (238.46±23.85), (224.52±26.01), (211.91±23.07) μm, respectively; the average choroidal thickness of the patients in the emmetropia group, the low myopia group, the moderate myopia group, and the high myopia group was (220.16±66.00), (252.39±79.56), (191.09±103.03), (121.83±92.54) μm, respectively. There was no significant difference in retinal thickness between the moderate myopia group and the high myopia group (P>0.05), while the differences in retinal thickness between the remaining groups were statistically significant (P<0.05); there was no statistically significant difference between the emmetropia group and moderate myopia group (P>0.05), while the differences in choroid thickness between the remaining groups were statistically significant (P<0.05). Conclusion In general, there are decreasing trends of the retinal thickness and choroid thickness with the increase of the diopter, which may be associated with the formation process of myopia.