The violuric acid mediated chemical delignification system has a high delignification efficiency for pulp fibers and high delignification selectivity. The process conditions and effectiveness were carried out.The kinetics of electrochemical delignification has been investigated using the violuric acid (VIO) as the mediator. The reaction orders with respect to delignification, concentration of VIO and voltage of electrolytic cell were determined experimentally, which were dependent on the reaction conditions. The kinetic equation of electrochemical delignification and estimation function of kappa number were obtained respectively as follows: - dK/dt = A e-VI1.0312.197K6.25 , E=16.2KJ/mol, K(t)={2.89×10-7+5.25k VI1.0312.197t}-0.19.