Numerical simulation of microbubble flow around an axisymmetric body was carried out in this paper. In the mathematic model, the flow with microbubbles was treated as mixture flow, the motion between bubbles and water together with buoyancy of bubbles were all taken into account. The distribution of microbubbles about the body and the drag reduction of the body were computed under different conditions, such as, using bubbles of different diameters, under different speeds of the body and bubble ejection rates. The computed results agree with the conclusions drawn from the published experimental studies. The analysis of the computed results indicates that the key of drag reduction by using microbubble is to produce bubbles little enough and keep them adhere to the body surface to maintain high void fraction.