The transverse momentum distributions of hadrons in 200GeV Au-Au collisions at RHIC are calculated using the smoothed particle hydrodynamics code SPheRIO. They are compared with data from STAR and PHOBOS Collaborations. By employing an equation of state which explicitly incorporates the strangeness conservation and introducing strangeness chemical potential into the code, the transverse spectra give a reasonable description of experimental data, except the multiplicities of hyperons.