Taking for an example the Reissner-Norstrom black hole, we reinvestigate its Hawking radiation of charged particles via tunneling, which is viewed from the laws of black hole thermodynamics. After rewriting the imaginary part of the action into the related functions of laws of black hole thermodynamics, we find that there is an underlying relation between the first and second law of black hole thermodynamics and Hawking radiation via tunneling based on Parikh and Wilczek's original works. Moreover, if we consider the tunneling process as a reversible process, the result in Hawking radiation via tunneling is consistent with the first and second law of black hole thermodynamics. In other words, Parikh's conclusion is only valid for the reversible process.