Morphometric observation on the ovarian follicles of ICR strain-female mice has been conducted to investigate the effect of induced inflammation on the follicular populations. Inflammation was induced by administering 25${mu}ell$ of turpentine oil intraperitoneally 2 times at the interval of 3 days. Mice showing 5-day estrous cycle about 20 days after induction of inflammation are placed in experimental group. Normal follicles of 100～399$mu extrm{m}$ in diameter increased at estrus but those of over 400$mu extrm{m}$ decreased. super-ovulation increased the number of normal follicles of over 400$mu extrm{m}$. The number of normal follicles of over 400$mu extrm{m}$ 48 hours after superovulation was not significantly different between experimental and control groups. Present results indicated that the number of preovulatory follicles 48 hours after PMSG injection did not decrease in the mice which showed regular estrous cycle even after the induction of inflammation.