Megasonic cleaning, which uses higher frequency wave at and above 1 MHz, have been studies for efficient cleaning without pattern damage in semiconductor industry. To clarify multi bubble dynamics in megasonic field, in the present study, numerical simulations of two and three oscillating bubble near wall boundary in megasonic field are performed using a compressible locally homogeneous model of a gas-liquid two-phase model. In the calculation of two bubbles with the initial radii of 2.0 μm, the oscillating amplitudes of the bubbles grow, the bubbles approach, coalesce, and induce the higher pressure. It is found that in the cases of two bubbles, the induced pressures in the case of R_0 ≥ 2.2 μm are smaller than these in the case of single bubble and these in the case of R_0 ≤ 2:0 μm are larger than these in the case of single bubble.