We present a new method to extract gate-bias-dependent source/drain resistance in MOSFETs. The extraction starts from a simple mobility model, but a more sophisticated mobility model is incorporated afterward. The method provides a convenient way to extract the source/drain resistance as well as parameters in a sophisticated mobility model. The extracted parameters in the mobility model vary with channel length. To satisfy some device modeling work where parameters independent of channel length are desirable, we also develop another technique so that a single set of parameters is obtained and is applicable to all channel lengths. The extraction techniques are useful for submicron MOSFETs without going through complicated procedure.