35 patients of normal reproductive age group (22-37 yrs) were selected for ovulation induction using $Clomid^{(R)}$ and HMG. Correlation between canalization of cervical mucus and estradiol level in plasma. morphological ovarian follicular change by ultrasonogram, Ferning and Spinnbarkeit were studied in the induced ovulatory menstrual cycles. By retrospective analysis, the results were following; 1. Canalization appeared on the eighth day of the menstrual cycle in $Clomid^{(R)}$ group, and seventh day of HMG group. And the number of the channels increased gradually until the ovulation time. 2. The mean number of channels increased from 12${pm}$12 in $Clomid^{(R)}$ group, 19${pm}$14 in HMG group (Day-6) to a maximum of 46${pm}$22 in $Clomid^{(R)}$ group (Day-1). 3. The maximum plasma estradiol(E2) level was 812${pm}$722pg/ml in $Clomid^{(R)}$ group (Day-1), 1792${pm}$504 pg/ml in HMG group (Day-1), and there was a good statistical correlation between the number of channels and the plasma E2 level. 4. The maximal follicular diameter was 19.4${pm}$6.7 mm in $Clomid^{(R)}$ Group (Day-1) 19.3${pm}$4.6mm in HMG group (Day-1) and after than decreased. There was a good statistical correlation between the number of channels and the follicular diameter. 5. When grade of ferning was I, the number of channels were 19.4${pm}$6.7 in $Clomid^{(R)}$ group, 38${pm}$26 in HMG group. When grade of ferning was III, the number of channels were 54${pm}$30 in $Clomid^{(R)}$ group, 71${pm}$36 in HMG group. 6. The maximum score of Spinnbarkeit was 2.6${pm}$0.5 in Clomid group (Day-0), 2.6${pm}$0.5 in HMG group (Day-2). In conclusion, the phenomenon of cervical mucus canalization showed the value of the clinical use as an ovulatin marker.