Objective To study the role of intramuscular phloroglucinol injection in relieving pain of aged patients undergoing hysterescopy. Methods Totally 130 aged patients (aged from 60 to 76 years old) undergoing hysteroscopy were evenly randomized into the phloroglucinol group and placebo group．The phloroglucinol group received phloroglucinol (80 mg i.m.) 5 min before undergoing hysteroscopy; the placebo group received intramuscular injection of normal saline (8 ml)．The pain degrees were measured by visual analog scales (VAS) in the two groups. The heart rate，blood pressure，and saturation of blood oxygen were observed before and 5 min after entering hysteroscope. Results The VAS score of phloroglucinol group was significantly lower than that in the placebo group (2.8±1.5 vs 5.1±2.1, P<0.05). The heart rate of the placebo group was significantly faster at 5 min after hysteroscopy compared with that before hysteroscopy (88.7±18.3/min vs 75.8±18.9/min, P<0.05)．There were no significant differences in the blood pressure and saturation of blood oxygen between the two groups. Conclusion Intramuscular injection of phloroglucinol can alleviate the pain in aged female patients undergoing hysteroscopy.