The chisness chester2-whitam3 method has been used to study the propagation of diverging cylindrical hydromagnetic shock waves through a self gravitaing gas in the presence of a magnetic field having only constants axia(HZ0) component, the problem is investigated for strong shock only. Assuming an initial density distribution p0=pirw wher r1 is the density at the axis of symmerty and a constants, the reaction for shock velocity and the shock strength pressure, particle velocity and density have been obtained.