An experiment on the transverse horizontal spatial coherence of sound propagating in the ocean was performed jointly by Chinese and Russian acousticians in the northwest Pacific Ocean in June 1990. Three hydrophones with spacings of 270 and 130 m were put in the water at a 30-m depth. The acoustic source with four cw (from 109 to 860 Hz) and a broadband pseudorandom noise signal was drifted at a depth of 100 m. Part of the measurement results of up to 140 km are presented in this paper. It seems that the spatial coherence was related to the amplitude of the received signals and rises considerably in convergence zones.