In this paper, an apparatus used to measure the surface tension at high temperature and elevated pressure was developed, based on the differential maximum bubble pressure method. As standard solvents, the surface tensions of methanol, ethanol, and benzyl benzoate were measured over a range of temperatures and pressures. The results were compared with the literature values, and the relative uncertainty of measurement is less than 2%. The surface tensions of benzene, toluene, p-, o-, m-xylene, and the binary mixture of p-xylene + benzene were measured at 1.6 MPa, from (80 to 200)degrees C.