Beam steering of leaky wave radiation from a nonreciprocal composite right/left handed transmission line with a ferrite substrate is proposed. The nonreciprocal phase constants of the line were tuned by changing the applied DC magnetic field normal to the ferrite substrate. In the numerical simulation and the experiment, the nonreciprocal phase characteristics and leaky wave radiation are investigated for the ferrite substrate with the magnetization not only in the saturated region, but also in the unsaturated region. The numerical simulation results are in good agreement with the measurement. It is confirmed that the beam directions of the obliquely unidirectional leaky wave radiation for two different power directions are continuously tunable.