Abstract: In order to get more local interfacial information as well as to further comprehend the intrinsic mechanism of two-phase flow under rolling condition,a method was proposed to measure the local parameters by using optical probes under rolling condition in this paper.An experimental investigation of two-phase flow under rolling condition was conducted using the probe fabricated by the authors.It is verified that the probe method is feasible to measure the local parameters in two-phase flow under rolling condition.The results show that the interfacial parameters distribution near wall region has a distinct periodicity due to the rolling motion.The averaged deviation of the void fraction measured by the probe from that obtained from measured pressure drop is about 8%.