Objective To observe the efficacy of modified Liangxue Huayu Recipe（ 凉血化瘀方） in the treatment of essential thrombocytosis. Methods A n of one trial was used. Pre-experimental testing was performed to a patient with essential thrombocytopenia to determine the patient’s observation period of 2 weeks and the elution period of 1 week. Three rounds of randomized double-blind self-controlled trials were performed. During the trial period

patients were given modified Liangxue Huayu Recipe

one dose per day

and a western medicine placebo（ vitamin C

0. 5 g per tablet） 30 mg/（ kg·d） for oral administration

once a day. During the control period

the patients were given hydroxyurea tablets 30 mg/（ kg·d） for oral administration and Chinese medicine control recipe

one dose per day. The platelet count and scores of the myeloproliferative tumor total symptom assessment scale（ MPN-10） in the trial period and the control period after the 3 rounds of the trial were compared. Results After three rounds of trials

there was no significant difference in the platelet count between the trial period（ 120. 67 ± 22. 03） × 10

9

/L and the control period（ 124. 33 ± 24. 09） × 10

9

/L（ P

>

0. 05）. The MPN-10 score during the trial period decreased（ 13. 00 ± 3. 61） which was significantly higher than that in the control period（ 10. 33 ± 3. 06）（ P

<

0. 05）.Conclusion Modified Liangxue Huayu Recipe is equal to hydroxyurea tablets in reducing the platelet count in patients with essential thrombocytopenia

but it is superior to hydroxyurea tablets in improving clinical symptoms.