This paper is concerned with the fluid force acting on a tube placed in a parallel steam-water two-phase flow. Based on experiments on the tube vibration induced by the turbulence of two-phase flow, the relationships between the hydrodynamic mass, damping ratio, excitation force, and the fluid flow conditions were evaluated. Mass flow rate, pressure, and void fraction were varied in the experiment to measure random vibration of the tube caused by turbulence in the stream. The hydrodynamic mass and damping ratio were derived by analyzing the vibration data. The excitation force was calculated using a transfer function to represent the relationship between the intensity and excitation force of the vibration given by random statistical theory. It was found that the hydrodynamic mass and damping ratio are little affected by the mass flow rate and pressure but are significantly affected by the void fraction and frequency. In contrast, the vibration excitation force is affected by the pressure as well as the effects of void fraction and frequency. The relationships between them were evaluated.