With the advance of science and technology and thedevelopment of the society, the world is evolved from theindustrial ages to eco-civilization era. The developmentof the social productivity, the improvement of human'sliving standards, the imbalance of urban and regionaleconomical development and the income gap result in thedifferent consumption level [1]. According to the currentsurvey, the demand for second-hand business transactionis very large; the maturity of the e-business technologymakes it essential to design online transaction system.