Spacecraft observations from the Earth's magnetotail show that the flaring angle depends on the downtail distance, the upstream solar wind dynamic pressure, and the Bz component of the interplanetary magnetic field [Petrinec and Russell, 1993>. Measurements from the Phobos 2 spacecraft along a circular orbit at 2.8 Mars radii allow a similar study of the Mars magnetotail. Under the assumption that the magnetic pressure in the Martian tail lobes is much greater than the plasma pressure in the lobe, we use the pressure balance condition between the tail lobe magnetic pressure and the normal component of the solar wind pressure to infer the angle at which the tail magnetopause flares. As in the case of the terrestrial magnetotail, the flaring angle of Mars tail depends on the solar wind dynamic pressure, but his angle (at 2.5 RM) is about one half the terrestrial value (at 17RE). The median inferred flaring angle is about 13¿. ¿ American Geophysical Union 1994