Previous calculations of turbulent magnetohydrodynamic (MHD) eddy viscosity and anomalous resistivity are reviewed. Emphasis is laid on a new approach to fully developed turbulence proposed by Canuto and Dubovikov, containing both systematic and heuristic elements for the ultraviolet (UV) and infrared (IR) parts of the nonlinear interactions in hydrodynamics. Their method is extended so that the magnetic and velocity fluctuations are treated on an equal footing. The effective magnetic Prandtl number is obtained as a function of the residual energy spectral density.