Abstract: In order to simulate the effect of seismic vibration on two-phase flow in reactor core, vibration experiments of local two-phase flow parameter distribution in an annular channel were carried out using four-sensor conductivity probes in this study. The vibration period of the eccentric cam with eccentricity of 15.875 mm can be adjusted by changing the motor speed. The inner and outer diameters of the annulus test section are 19.1 mm and 38.1 mm, respectively, and the total length is 2.32 m. An adiabatic air water two-phase flow was used in the experiment and the flow condition covered bubbly flow, slug flow and churn-turbulent flow regimes. The experiment results show that the vibration has very important effect on two-phase flow parameters such as void fraction and interfacial area concentration. The two-phase parameter distribution changes greatly with the decrease of vibration period. In addition, the vibration has very obvious effect in bubbly flow regime but this effect decreases as the flow transit into churn-turbulent flow.