YU, WF (reprint author), INST HIGH ENERGY PHYS,HIGH ENERGY ASTROPHYS LAB,BEIJING 100039,PEOPLES R CHINA.
The stability of an isothermal magnetized accretion disc with radial viscous force is examined in this paper. We confirm the former conclusion that viscous stress acting in the radial direction damps the radial oscillations. We also find that consideration of the radial viscosity does not give rise to any new mode of instability. The radial magnetic field is important to disc instability if the vertical component of the magnetic field is zero.