Large-signal models using extracted parasitic resistances are proposed for multi-finger MOSFETs and the statistical variations of parasitic resistances are investigated using statistical modeling. The extracted model parameters for the proposed models are verified with measured data. The models can explain the large-signal characteristics of multi-finger MOSFETs. Using the equivalent circuit model, the characteristic variations are statistically modeled with varying the gate layout factors and the extracted parasitic resistances. Based on the results, the gate geometry and extracted parasitic resistances, which are closely related to the source bias, can impact on the characteristic fluctuations of multi-finger MOSFETs.