The objective of this study is to induce and measure the human stress level through computerized mental arithmetic task and multiple physiological signals (ECG, EMG, GSR, and skin temperature). Studies suggested that mental arithmetic task is one of the efficient stimuli to induce the stress. Hence, this mental arithmetic task protocol has been improved in to computerized version. The protocol will be tested with normal subjects and multiple physiological signals will be acquired simultaneously. The questionnaire about the subject experience will be obtained in order to strengthen the stress induction. The normal volunteer subjects will be invited for the participation this study. The physiological signal will be analyzed using suitable algorithm based on the characteristics of each signals. The multiple signal based stress level assessment system will be developed by training and testing the acquired data.