The transportation system by hydraulic capsule would be applied in the port and harbour area because it has some advantages in the environmental preservation and saving energy. Therefore, fundamental experiments of cylindrical capsules were conducted to investigate the coefficient of drag and flow characteritics in the pipeline. 　The following main conclusions were obtained through this study. (1)With the increase of the ratio of capsule and pipe diameters, the coefficient of drag of cylindrical capsule in the pipe increases rapidly and has the tendency of having little concern with the eccentricity. (2)As to the acceleration of capsule, the capsule velocity usually reaches at the final constant value in a short time. On the other hand, the differential pressure of the pipeline vibrates greatly and it takes relatively long time to diminish. (3)It is possible to predict the minimum capsule velocity, in which no lift force acts on capsule, using the coefficient of drag of capsule and the coefficient of moving friction between capsule and pipe.