When a solid object is inserted in a flow field containing many buoyant rising bubbles, a variety of two-phase flow patterns appear around the object due to interaction between the rising bubbles and surrounding liquid flow. A quite unique flow pattern similar to a shock wave is observed in the case of high void fraction and large bubbles suspended. However, the detailed mechanism of the affection of such object on its ambient flow pattern has not been elucidated. The present paper is concerned with the numerical investigation on various wake structure downstream of a cylinder which is fixed in a rising bubbly flow. The Eulerian-Lagrangian model is adopted to predict the two-phase wake structure interacting the cylinder and shows two-kinds of interesting phenomena. One is the generation of negative force acting on the cylinder against bubble-rising direction because of formulating a large liquid single-phase region downstream of the cylinder. The bubble distribution pattern agrees with experimental results. Second one is the vanishing of Karman vortex shedding in an upward flow owing to a thin bubble layer near the cylinder surface.