ABSTRACT During the MC, women are exposed to continuous variations in serum concentrations of several female sex steroid hormones. Estrogen, progesterone, follicle stimulating hormone (FSH), and luteinizing hormone (LH) are essential to regulate the patterns of the ovulatory cycle. The perpose of the current study was to investigate the impact of the menstrual luteal phase on instanteous muscle torque. Observational cross-sectional was used in the present study. Females were selected from the Egyptian Chinese university students. Thirty females within 14 days after last menstruation and during menstruation were recruited in the present study. They were selected from the Egyptian Chinese University students. Patients assigned to one group, the selected 30 females were measured within 14 days after last menstruation and during menstruation, they were all assessed by isokinetic device to detect the strength and instantaneous muscular torques of knee extensor during LP. There was significant decrease in right and left knee extensor strength and Peake muscle torque compared with the menstrual phase. It could be concluded that physical performance is affected by the different phases of menstrual cycle in the defined group. But it may vary according the physiological, psychological and environment condition of each participant.