Abstract: OBJECTIVE To investigate the change in thermoduric bacteria count of Uncaria rhynchophylla and Perilla frutescens as heating time increased, in order to provide data support for the establishment of related standards. METHODS According to the microbial limit test method for Chinese herbal medicine of Chinese Pharmacopoeia 2020 edition(draft amendment), the suitability of the counting method of these two herbal medicine was examined. Then the amount of thermoduric bacteria were determined at different boiling bath time. The surviving thermoduric bacteria were isolated and identified for an inactivation test. RESULTS The results were in compliance with 1107 general chapter of Chinese Pharmacopoeia 2020 edition(draft amendment). The counts of thermoduric bacteria were significantly reduced as boiling bath time increased. The identification results indicated that all the thermoduric bacteria belong to the Bacillus. CONCLUSION Chinese herbal medicines are contaminated by thermoduric bacteria, a reasonable thermoduric bacteria control standards shall be established to ensure the safety of medication.