It has been reported that perceived reversals of a rotation direction of a simulated cylinder occur due to ambiguity of the interpretation of which of motion surfaces is front than another. To investigate what kind of factors can give a solution to define 3D structure, here we tested effect of contrast of dots against a background on motion surface labeling. We simulated a transparent rotating cylinder. The simulated surface of the cylinder was covered by 80 dots whose luminance was either varied with the sinusoidal manner at the range of 6.3 to 71.5 cd/m^2 or fixed at 0 cd/m^2. The cylinder was presented on a background at either 77.8 (W condition) or 0.0 (B condition) cd/m^2. When dotsﾕ luminance was fixed, most observers perceived both directions of the rotating cylinder with an equal probability. However, the dominant perceived direction of the cylinder depended on the background condition when dotsﾕ luminance was varied. That is, the perceived direction under W condition is opposite to that under B condition. This indicates that contrast against the background has an important role giving depth information to define 3D structure of the cylinder.