OBJECTIVE： To establish the quality standard of Hirudo nipponica freeze-dried powder （called “freeze-dried powder” for short）， and to provide reference for controlling its quality. METHODS： A total of 3 batches of freeze-dried powder were collected， identified and tested according to the requirements of H. nipponica stated in 2015 edition of Chinese Pharmacopoeia （part Ⅰ） （shorted for pharmacopoeia）； the antithrombin activity was also analyzed. The maximum tolerated dose （MTD） was used to investigate the toxicity. The stability was determined by designing temperature， humidity and strong light exposure tests. RESULTS： In the TLC of test sample， the same red spots were found in the corresponding location of the control drug chromatogram， and the same orange-red fluorescence spots were shown under the UV light （365 nm）. Average content of moisture in 3 batches of samples was 2.61％， and the levels of total ash， acid-insoluble ash， pH aflatoxin and antithrombin activity were 2.83％， 0.38％， 6.92， 0.28 μg/kg and 257.0 U/g， respectively. The content of Pb， Cd， As and Cu were in line with the requirements of pharmacopoeia except that the content of Hg was slightly higher than lower limit of H. nipponica in pharmacopoeia. Results of MTD showed that no death and ADR was found in mice after giving 26.4 g/kg freeze-dried powder by the amount of crude drug， which was 58 times as large as the maximum dosage that the pharmacopoeia described. Under the condition of 20， 40 ℃ and strong light exposure [（4 500±500） Lx]， the anticoagulase activity of freeze-dried powder decreased significantly over time， while the anticoagulase activity of freeze-dried powder stored at 40 ℃ for 6 months was in line with the requirements of pharmacopoeia. Under the condition of high humidity （relative humidity were 90％， 75％）， freeze-dried powder showed a strong hygroscopicity. CONCLUSIONS： Established quality evaluation standard for freeze-dried powder according to pharmacopoeia standard could be used to control its quality.