Arccording the general covariant equation of motion and Maxwell equations, we derive the analytical expressions for various quantities of electron plasma wave. It is pointed out that the plasma wave with △ω = 2ωp is completely harmonic. The condition of complete resonance is given by △ω= 2ω(p0) 1+(e2(A2((1)2)+(A2((2)2))/(2m2c4)+(3e2A2(1)A2(2))/(m2c4)-1/2.