The paper contains the results of a new experimental study of one- and two-phase massic heat capacities at constant volume cv and (liquid + gas) coexistence of propane near the critical point. The measurements cover the range in temperature from 288 K to T-c. The measurements were made in a high-temperature and high-pressure adiabatic constant-volume calorimeter. Uncertainties of the measurements are estimated to be within + 0.02 . c nu. An analysis is presented of the experimental values of cv and coexisting (vapour + liquid) densities in the critical region of propane. The model used is that of extended scaling, as given by the modern theory of critical phenomena. From the experimental results, the thermodynamic properties (p(s) rho(s),S,H,c nu,c(p),(j),W,kappa tau,Delta(vap)h) of propane near the critical point were determined. Detailed comparisons of these thermodynamic properties with independent experimental and calculated values of other authors are presented.