Objective: To study the effects of Chinese medicine telramethylpyraze (TMP) on intracellular free calcium (\
i ) in cultured penis corpus cavernsum smooth muscle cell (PCSMC) in rabbits. Methods: By using laser scanning confocal microscope (LSCM), the \ i fluorescence signal changes was investigated in cultured PCSMC loaded with Ca 2+ indicator Fluo 3/AM and divided into potassium chloride(KCl) group and norepinephrine (NE) group. Compared with verapamil (Ver), the effects of TMP was observed in different concentrations on \ i increase induced by high potassium and NE. Results: TMP had no obvious effect on resting PCSMC \ i . It was found that 1, 10, 100 μmol/L TMP significantly inhibited \ i increase induced by high potassium depolarization. The peak inhibition rates were ( 38.6 ± 3.0 )%?( 44.1 ± 2.4 )% and ( 53.7 ± 4.1 )% respectively. TMP could also inhibit cytosolic calcium pool release induced by 1 μmol/L NE. The peak inhibition rates were ( 13.9 ± 2.7 )%, ( 21.2 ± 1.9 )% and ( 29.5 ± 3.6 )% respectively. Conclusions: TMP can inhibit rabbit PCSMC \ i significantly by suppressing voltage dependent calcium channel and cytosolic calcium pool release. The effect, similar to Ver, signifies the important mechanism of erectile dysfunction (ED) therapy.