Self-control is the ability to attain deliberative control over impulses and abstain from gratifying immediate needs and desires. The strength model of self-control is the most influential theory of explaining the failure of self-control. The strength model indicated resources used for an initial self-control attempt are no longer available for later attempts, resulting in decreased self-control performance. This phenomenon is labeled ego depletion and has been demonstrated in a wide range of studies. The prior studies on strength model focus on different tasks sharing the limited resource. The present study explored whether the same task exerted different modality share the limited resource. The authors adopted the dual-task paradigm through two experiments to validate the modality effect in ego depletion. In Experiment 1, the first task was the working memory task which executed through auditory or visual modality, and the second task was the physical stamina tasks which exerted independent of auditory and visual modality. In Experiment 2, the first task was the working memory, and the second task was the Stroop task which exerted through visual modality. The results of experiment 1 showed that participants who completed visual depleted task performed worse at the second handgrip measure than participants who completed visual non-depleted task, and there is no significant difference at the second handgrip measure between participants who completed auditory depleted task and auditory non-depleted task. The results of Experiment 2 were the same as the ones of Experiment 1. The experiment 1 and experiment 2 indicated implementing the same self-control task through different modality depleted unequal resource, so had different effect on a subsequent task of self-control, which validated the modality effect of ego depletion.