Abstract: By using the model of the tri-axial ellipsoid and theoretical calculations of un-uniform wind loss, the evolution of the rotational binary system is simulated numerically and analyzed. The results have shown that the time of the beginning of mass transfer phase and the central hydrogen-burning phase advanced, the main sequence is wider, the evolution track in the HR diagram shifted towards lower luminosity, a large amplitude of bluer track is caused, the radius has periodic expansion and contraction in the slow mass transfer process, and the angular momentum loss rate is smaller.

Key words: the model of tri-axial ellipsoid, mass loss via stellar wind, the rotational binary system, evolution