Abstract: OBJECTIVE To observe the clinical efficacy of Dahuang Zhechong Pill in the treatment of blood stasis syndrome due to JAK2-V617F positive polycythemia vera (PV) and its influence on the expression of tumor angiogenesis-related factors. METHODS A total of 43 patients were enrolled and randomly divided into 21 cases in the control group and 22 cases in the treatment group. Ten patients with immune thrombocytopenia served as blank controls. The control group received oral hydroxyurea， and the treatment group was treated with Dahuang Zhechong Pills on the basis of the control group. After 3 months of treatment， applying the myeloproliferative neoplasms symptom assessment form total symptom score (MPN-SAF-TSS) and blood-stasis syndrome score form to evaluate the clinical efficacy and adverse reactions of patients in the two groups， as well as compare the indexes before and after treatment， including the expression levels of bone marrow Williams tumor gene (WT1)， vascular endothelium growth factor (VEGF)， cyclooxygenase-2 (COX-2) and microvessel density (MVD). RESULTS After treatment， the MPN-SAF-TSS evaluation scores of the treatment group decreased after treatment (P<0.05，P<0.01)， fatigue， weight loss， abdominal discomfort， inattention， skin itching， and bone pain were significantly improved， which were better than the control group (P<0.05，P<0.01). After treatment， the symptoms of blood stasis， concretion， and signs of tongue proper in the two groups were improved significantly (P<0.05，P<0.01)， and the treatment group was better than the control group (P<0.05). The effective rates of the two groups were 77.3% and 61.9%， respectively， and the treatment group was better than the control group (P<0.05). There was no statistical difference in adverse reactions between the two groups (P>0.05). Compared with the blank group， the expressions of WT1， VEGF， COX-2， and MVD in the two groups were high before treatment (P<0.05)， but lowered after treatment (P<0.05，P<0.01). The decreased levels of WT1， VEGF， COX-2 in the treatment group were better than those of the control group (P<0.05). CONCLUSION Quyu Liangxue prescriptions are effective in treating PV， and it can inhibit WT1 gene expression and tumor angiogenesis. There is no obvious adverse reaction， which is worthy of further research and promotion.