As well known, the measurements of the sound attenuation on a single bubble can be explained by thermal conductivity, viscousity and radiation losses. But when the measurements were made in a bubble screen, it will not be so simple. Since the theoretical loss is much less than the measured one, this problem is open until now.In this paper, taking the sound interaction among bubbles in water into account, a 90 phasor between the primary incident sound and the multi-scattering sound has been ob-tained. The latter is equivalent to a retard force acting on every bubble, and they suffer an additional damping.Comparing our theory with Carstensen and Foldy's experiments, a satisfactory agreement has been, found. In addition, we point out that the resonant frequencies of bubbles do not vary with the interaction among them, but the resonant curves will be widened. When the sound frequency is lower than the resonant frequency of a bubble, the mass which accompanies it will get an increase and the stiffness get a decrease. When the sound frequency is higher than its resonant frequency, the situation will be converse.