Abstract: For saturated-unsaturated water table flow, computations of ADEP, ADIP and implicitly alternating direction iterative procedure are made and compared.The i-terations are not convergent and computational results are strongly distortional Based on supplementing a particular term, a kind of completely implicit and altern-ting direction iterative procedure is given The relative results for computational model of different scales are satisfactory. Problems of how to give the particular supplemental term and how to select better parameters are discussed, the computational results are given.