Background: A number of effective prevention measures have been introduced in attempts to substantially reduce both the incidence and mortality due to many kinds of cancer. The search for new anti-cancer compounds in foods or in plant medicines is one realistic and promising approach to prevention. Chinese medicines provide a rich pool of novel and efficacious agents for cancer prevention and treatment. Previously it was demonstratrated that hyperin extracted from the Manchurian rhododendron leaf reduces the proliferation of many cancer cells. The present study was carried out to evaluate its effects on human endometrial cancer cell viability and apoptosis and to investigate its mechanisms of action in RL952 cells. Methods: Cell viability was measured using the MTT assay. Intracellular calcium ions were detected using laser-scanning confocal microscopy. The effects of hyperin on apoptosis related proteins in RL952 cells were examined using Western blot analysis. Results: The growth of RL952 cells was inhibited by treatment with hyperin. OD values of caspase-3 and caspase-9 were increased and expression of bcl-2 was increased and bax was decreased in protein levels in RL952 cells after 24 h of hyperin treatment, Moreover, intracellular calcium accumulation occurred in hyperin-treated cells. Conclusion: These results suggest that hyperin may play an important role in tumor growth suppression by inducing apoptosis in human endometrial cells via a $Ca^{2+}$-related mitochondrion apoptotic pathway in RL952 cells.