Many scholars conduct comprehensive researches on the mobile commerce acceptance in the perspective of users after it comes into being. It is meaningful to understand the acceptance of users in terms of mobile technology itself when it is immature. This paper concludes four characteristics of Wireless mobile office and proposes an extended technology acceptance model which incorporates trust in the perspective of technology maturity. It proves that trust plays an important role in mobile office service. And also this paper introduces what technology factors determines mobile office service acceptance of companies, which provides evidence to develop new technology for mobile technology suppliers. Meanwhile, it provides a new perspective for mobile office service users to make useful strategies and maintain their competitiveness and market share.