【Abstract】 Objective To explore the inhibitory effect and regulatory mechanism of water extract of Capillary wormwood herb on zebrafish neovascularization. Methods 90 embryos of 22 HPF normal development zebrafish were collected from fli1a EGFP transgenic zebrafish of TG strain. They were divided into blank control group, positive control group and Capillary wormwood herb water extract group. The blank control group was given 0.1% DMSO, the positive control group was given 5 μg/ml vatarani, the water extract group was given 200 μg/ml. The vascular phenotypes of zebrafish embryos treated with the extract of Artemisia Capillaria were observed and photographed under the body fluorescence microscope, and the effects of the samples on the formation of the internode vessels (ISVs) of zebrafish were analyzed. The expression of PTP Rb, nr2f1a, VE cadherin, S1P1, CD146, pik3r2, netrin1a, fgfr1a, FGFR2, FGFR3, FGFR4 genes in the treated fish embryos was detected by realtime fluorescence quantitative PCR. Results Compared with the blank control group and the positive control group, the ISVs of the fish embryo in the water extract group of Artemisia Capillaria became thinner and the sprouting of the dorsal aorta decreased, showing the inhibition effect on the angiogenesis of zebrafish (P＜005). The nr2f1a gene of the water extract group was down regulated, but there was no significant difference compared with the blank control group and the positive control group (P＞005), PTP Rb gene was down regulated, the difference was statistically significant (P＜00001). The expression of VEcadherin, S1P1, CD146, pik3r2, netrin1a, fgfr1a, fgfr2, fgfr3 and fr4 increased, But there was no significant difference between the two groups (P＞005). Conclusion The water extract of Capillary wormwood herb can inhibit the neovascularization of zebrafish, and its mechanism is related to the downregulation of PTP Rb gene expression.