In this study a three-dimensional fnite element model is presented for precisely simulating laser cladding process with a focus on dilution control. Dilution is referred to as an important quality index in the laser cladding process, indicating the contamination level of the properties of clad layer by substrate metals. As regards a good quality of laser clad layer, low dilution as well as metallurgical bond of interface are prerequisite, so the dilution control is essential in the process. Unfortunately despite of its importance, to date, any practically usable computation techniques have not been reported, which is a motivation of this work. In the paper, proposing a simulation procedure, we develop and verify a code of !nite element method with Lagrangian view-point. Following the procedure, the dilution control is precisely estimated. The effects of process parameters on the dilution of clad layer are quantitatively discussed by the numerical and experimental means.