Results that follow from the theoretical analysis and numerical calculation of the thermodynamic properties of vapour R134a in terms of the Martin-Hou equation of state are given. In particular, the study is concentrated on properties that are usually not published. The influence of both temperature and pressure (that accounts for the gas compressibility effects on pvT vapour behaviour) on either property calculated for HFC-134a is established. The obtained results are compared with the theoretical results of other authors. The deviation are within a 1 % range.