The purpose of this paper is to introduce a new implicit fractional step altorighm of two processes for the calculation of the transport equations of fluid flows i.e., the convection-diffusion process and propagation process.It is found that the second step of the propagation process in the present method resembles the velocity-pressure correction procedure in the SIMPLE-like methods, and the SIMPLEC algorithm is a special case of the proposed method. Two numerical examples of laminar flows show that the rate of convergence can be significantly improved by the change of the optimal coefficient α.