Surface dynamic change during the Wilhelmy force measurement was investigated for microscope cover glasses coated by trimethylsilane (TMS) and TMS + oxygen plasma polymers. The intrinsic hysteresis which is caused bg the surface configuration change on water immersion can be detected by the deviation of shape of the force loop. The deviation of the second immersion line from the first immersion line and also of the initial slope of the second immersion (in the transient stage where the change of meniscus takes place) can be taken as a measure of the existence and the extent of the surface dynamic changes due to water immersion. These parameters are dependent on the speed of immersion or emersion employed in the force measurement and can be enhanced by halting the motion at the end of immersion or emersion.