Abstract: This paper presents a comparative analysis on the rapid estimation of ship resistance， putting forward a corresponding method for full ships with different tonnages. Combining the model trial data of new type ships with different tonnages provided by domestic authorities in recent years， this paper compares the result with model test data. It is concluded that the Lap-Keller method is more applicable to large tonnage ships under mid-high speed， while the Ayre method is more applicable to small tonnage ships under middle-low speed.