Abstract:For the nondegenerate smooth map between manifolds, by using the divergence formula on fibre of the projective sphere bundle, another simpler way to prove the first variation formula of the energy functional is given. At the same time, the relations between the second fundamental forms (resp. the mean curvature) of Finsler metric and that of Riemannian metric in Randers spaces are discussed. At last, a classification theorem of strongly minimal submanifolds in Randers spaces is given.