Numerous C0 discontinuous Galerkin (DG) schemes for the Kirchhoff plate bending problem are extended to solve a plate frictional contact problem,which is a fourth-order elliptic variational inequality of the second kind.This variational inequality contains a nondifferentiable term due to the frictional contact.We prove that these C0 DG methods are consistent and stable,and derive optimal order error estimates for the quadratic element.A numerical example is presented to show the performance of the C0 DG methods;and the numerical convergence orders confirm the theoretical prediction.