A separate and distinct interaction with both the actual e-vendor and with its IT web site interface is at the heart of online shopping. Previous research has established, accordingly, that online purchase intention is the product of customer assessments of IT itself, specifically its perceived usefulness and ease-of-use(TAM). Since perceived usefulness and perceived ease of use are such a fundamental driver of usage intentions, it is important to understand the determinants of this construct and how their influence changes over the voluntariness towards the usage intention. The reason for voluntariness as a moderating variable is that it had the serious effect to the motivating in the making willingness of the internet shopping-mall usage. A better understanding of the determinants of perceived usefulness and perceived ease of use to the usage intention would enable us to design web site interventions that would increase user acceptance and usage of internet shopping-mall. Therefore, the goal of the present research is to extend TAM to include additional key determinants of TAM and to understand how the effects of these determinants change with the voluntariness of the usage intention of the internet shopping-mall.