A compact buoy-array-type wave energy converter called multi-heaving-buoys (MHB) is introduced in this study. The hydrodynamic performance of MHB under regular wave conditions was first investigated experimentally in a wave tank located in Ocean University of China. It was found that a limited number of heaving buoys had little effect on the wave fields around the device. The small period of the incident waves caused an intense interaction between the waves and the buoys. The phase difference between the buoys in different rows was determined by the distance between the buoys. It was found that the response amplitude operator of the buoys varied from 0.6 to 1.2. Correspondingly, the range of the averaged relative velocity of the heaving buoys was 0.6-1.3. The upper limit of the acceleration of the buoys' motion was 0.2 times that of gravity. All of the experimental results provide valuable information for the future design of the hydraulic pressure power take-off systems. Copyright (c) 2017 John Wiley & Sons, Ltd.