General pharmacological properties of l-muscone, the major component of musk, were investigated in mice, rats and guinea pig. The administration of l-muscone (1, 10, 100 mg/kg, p.o.) in mice had no effects in general behaviors, and no influences on analgesic actions and normal body temperature. Muscle relaxant action, intestinal propulsion and gastric secretion were not observed even at the high dose of 100 mg/kg. l-Muscone (l, 10, 100 mg/kg, p.o.) given to conscious rats showed no effect on mean blood pressure and heart rate. It showed no direct effect at 2.4 x 10^(-3) mg/ml and 2.4 x 10^(-2) mg/ml in isolated uterus of rats and ileum of guinea pig, and also had no inhibition of contraction induced by oxytocin and histamine.