In view of the present shoaling calculation method in the Code of Hydrology for Sea Harbor,a practical calculation method (PCM) of wave shoaling was proposed in the partⅠof this paper.It was used for the shoaling calculation of a cnoidal wave propagating in a straight line.On the basis of the research in the partⅠ,wave refraction caused by variations in bathymetry is considered.Thus,the PCM method is extended to be able to compute shallow wave parameters over slowly varying bathymetry.In the final section,a numerical example is given.It is solved with the PCM method under different external factors conditions (ideal condition,wind,bottom friction and wind & bottom friction) separately.The results are compared with those obtained via the commercial software DHI-MIKE21,and proved to be in good agreement in terms of wave parameters values.