Due to a purely repulsive conservative interaction adopted in the traditional dissipative particle dynamics, the vapor-liquid coexistence phenomena or fluid flows with free surfaces could not be simulated. In the present study a recently proposed combination of short-range repulsive and long-range attractive interaction for DPD was investigated to explore its ability of simulating vapor-liquid coexistence or fluid flows with free surfaces. With this modified interaction, steady vapor-liquid interface could be obtained in DPD simulation, and the stress distribution across the vapor-liquid interface region was also discussed, which were found in accordance with those obtained by multibody DPD. Furthermore, surface tension of vapor-liquid interface was studied, and it was verified that Laplace’s law is satisfied in our simulation. Surface tensions obtained by theoretical method and Laplace’s law, respectively, are in agreement with each other.