The probe beam can be indued focusing by the pump beam that results from crossphase modnlation mechansim(XPM). Found by Agrawal in 1990,it was stduied by many people. We discuss the evolution of Gaussian beam with the angle of incidence in(1+1)dimensional self-defocusing media. The numerial results show that there exists an optimal value for the angle of incidence on the induced focusing of optical beams in self-defocusing media. The results are useful designing experiments in order to obtain the best effect of the focusing.