In this paper, the effects of penetration rate on cone resistance in saturated clayey soils were investigated by performing miniature cone penetration tests in a calibration chamber. These tests, using both a conical and flat-tip penetrometers, were performed at different penetration rates in two specimens prepared by mixing kaolin clay and Jumunjin sand with different mixing ratios and consolidated to a K0 condition. The mixing ratios of these two specimens were decided based on results of flexiblewall permeameter tests performed on clayey sand mixtures prepared at various mixing ratios. A correlation between cone resistance and drainage conditions was established based on the cone penetration test results. The transitions from no drainage to partial drainage and from partial drainage to full drainage were defined as a function of penetration rate normalized with respect to the penetrometer diameter and the coefficient of consolidation.