Abstract： Objective:To investigate the clinical characteristics, treatments and prognosis of ocular toxoplasmosis (OT).Methods:A retrospective clinical trial. Twelve cases (14 eyes) with OT which was confirmed by clinical and laboratory tests were included in the Department of Ophthalmology, Taihe Hospital in Shiyan and the Department of Ophthalmology, Beijing Chaoyang Hospital in Beijing from July 2011 to June 2019. Among the 12 cases, 6 cases were female (7 eyes) and 6 cases were male (7 eyes). The mean age of the participants was 33.4±12.8 years and the duration of illness ranged from 7 days to 30 years. Fungal endophthalmitis, viral uveitis and non-infectious uveitis were misdiagnosed in 2 cases respectively at the first visit. All the patients underwent BCVA, intraocular pressure, slit-lamp microscope, fundus color photography examinations and toxoplasma-specific serological antibodies tests. Intraocular influid were detected for 7 cases, among which 1 case for antibody only, and 6 cases for Goldmann-witmer coefficient (GWC). Of the 6 cases tested for GWC, 4 cases were tested with PCR assay in the ocular fluid addtionally. FFA was performed in 5 cases (6 eyes) and OCT in 6 cases (6 eyes). Eleven cases were treated with antitoxoplasma therapy. The follow-up duration after treatment varied from 1 week to 39 months. BCVA, clinical features and prognosis were retrospectively analyzed.Results:Specific antibody seropositivity of Toxoplasma gondii was detected in all 12 patients. Of the 7 cases tested with intraocular fluid, 1 case was IgG positive and the other 6 cases with 5 cases with GWC >4 and 1 case with 2<GWC <4. Only 1 case (25%) was positive among 4 cases with PCR assays meanwhile. BCVA was: <0.1 in 4 eyes, 0.1~0.3 in 6 eyes and >0.3 in 4 eyes. KPs with or without anterior chamber flash or cells could be detected in 6 eyes,congenital macular defect 1 eye, vitreitis 3 eyes (2 eyes with multiple retinal pigmentation foci and 1 eye with tractive retinal detachment), and coexistence of new and old lesions with Kyrieleis arteritis 2 eyes. Nine eyes showed different degrees of vitreous inflammation (75% of 12 active eyes). Single lesion was present in 4 case (4 eyes) and multiple lesions were present in 8 cases (10 eyes). There were no statistically significant changes in BCVA of OT patients before and after treatment ( P=0.83). Involvement or adjacent to macula of he primary lesions, misdiagnosis and mistreatment led to the poor prognosisi of visual acuity. Conclusions:The fundus of OT can show single lesion or multiple lesions, and the active phase is often accompanied by vitreous inflammation. The primary lesion involves or is close to the macular area, misdiagnosis and mistreatment are the main reasons for the poor visual prognosis of patients.