This article reviews the effects of VDT tasks on multiple resources for processing and storage in short-term working memory. MD and PD method were introduced toevaluate the modalities (auditory-visual) in the multiple resources model. The subjects conducted 2 sessions of 50 minites VDT tasks. Before, between and after VDT tasks, MD, PD task performance scores and CFF(critical flicker frequency0 values were measured. The review suggested that the modalities of human information processing in working memory were affected by VDT tasks with different task contents.