Aims To investigate the progression pattern of diffuse chorioretinal atrophy (DCA) among Chinese participants with high myopia. Methods This is a longitudinal, non-interventional study. Participants with high myopia, defined as ≤−6 diopters spherical power, were included and followed up for 4 years, and underwent cycloplegic autorefraction, best-corrected visual acuity (BCVA) and fundus photography examinations. Newly established DCA, enlargement of existing DCA and development of other lesions of myopic maculopathy were regarded as DCA progression. Results Of the 484 participants with a mean age of 21.5±12.7 years (range, 6.8–69.7 years), 68 eyes (14.0%) showed DCA progression, with 88 lesion changes. The first appearance of DCA was identified in 21 eyes (23.9%). Of 88 eyes with DCA at baseline, 47 eyes (53.4%) showed progression, with 67 lesion changes, including 45 eyes (67.2%) with enlargement of DCA, 17 (25.3%) with a first appearance of lacquer cracks, 4 (6.0%) with development of patchy chorioretinal atrophy and 1 (1.5%) with increased numbers of lacquer cracks. Longer axial length (p<0.001), baseline DCA (p=0.005) and baseline DCA closer to the fovea (p=0.013) predicted DCA progression. Eyes had poorer BCVA at the follow-up if DCA was enlarging (p<0.001) or DCA was closer to the fovea at baseline (p=0.028) after adjusting for age,gender and cataract. Conclusion Approximately half of the participants with DCA had progression over a 4-year follow-up. Enlargement and newly developed DCA were common progression patterns. Larger areas of DCA and foveal involvement with DCA could be indicators of a worse BCVA later.