Objective: To investigate the progression of visual field defect in primary open angle glaucoma (POAG), and to explore the related risk factors for its progression. Methods: A retrospective analysis was performed on patients with POAG who had at least 4 visual field examinations in the Department of Ophthalmology, Peking University Third Hospital from January 2014 to July 2018. The visual field was staged according to the mean deviation or mean defect of the first visual field examination. Linear regression analyses of mean deviation or mean defect were performed against time, and corresponding regression slopes (in decibels per year) were calculated. Patients were divided into progressive and non-progressive groups according to the mean deviation slope or mean defect slope. The relationship between retinal nerve fiber layer (RNFL) thickness lesion location, mean follow-up interval, baseline visual field staging, and the progression of visual field defect in glaucoma were analyzed. Results: A total of 128 patients (252 eyes) were included. Among them, 129 eyes were followed up with an Octopus perimeter, and the average mean defect value of the baseline visual field was 10.91±5.76 dB; while the other 123 eyes were followed up with a Humphrey perimeter, and the average mean deviation value of the baseline visual field was –10.62±6.89 dB. The proportion of early, middle and late visual field defects was 26.19%, 36.51% and 37.30%. There were 31 eyes (12.30%) in the progressive group and 221 eyes (87.70%) in the non-progressive group. Patients with severe damage to both the upper and lower RNFLs had more visual field defects (P<0.001). Patients with an average follow-up interval ≤4 months had a higher rate of progression than those with an average follow-up interval >4 months (P=0.058).There were no significant differences in baseline visual field stage, age, gender, and total follow-up time between the progression and progression-free groups. Conclusion: Deterioration of visual function impairment is common in glaucoma patients. The progression of visual field defects is associated with severe impairments which are present both in the upper and lower RNFLs, and short follow-up intervals. Optic nerve structure changes are related to functional impairment, and the location of structural changes is suggestive of functional impairment progression.Regular follow-up visits are of great significance for disease monitoring. For patients who may progress rapidly, the follow-up interval should be shortened.