Purpose: To analyze the efficacy of three different doses of bevacizumab treatment on Threshold retinopathy of prematurity during different periods . Methods: 36 cases (72 eyes) of infants with threshold ROP were analyzed, whom were treated with intravitreal injection of 1.25 mg, 0.75 mg or 0.5 mg bevacizumab respectively from October 1st, 2016 to September 30th, 2017. After treatment, fundus examination results during five time points were recorded and classified into four grades according to the efficacy. Results: There were significant differences in the changes of fundus among the 3 groups from the 4th day to the 4th week after treatment (P<0.01). In the 1.25 mg group, there was a significant difference in the changes of fundus on the 4th day after treatment VS. the 2nd week after treatment (P<0.001). In the 0.75 mg and 0.5 mg group respectively, the changes of fundus were significantly different between each consecutive time points of the 4th day, 2nd week, 4th week and 2nd month after treatment (P<0.001,P=0.001,P=0.002; P<0.001,P=0.001,P=0.003). The proportion of normal retinal vessels respectively in 1.25 mg , 0.75 mg and 0.5 mg group is 66.67%、43.48% and 50% in the 3rd month after treatment.Conclusion: Retinal complete vascularization was slightly better in 1.25 mg group, but failed to reach a statistical significance. Based on results, the lowest dose 0.5 mg may be preferred since our final results were similar (p>0.05). Long-term follow-up of fundus changes was still needed to avoid recurrence of ROP whatever the dose of bevacizumab was uesed.