Alertness is a key precondition for opportunity recognition. However, models of alertness are still immature because of theoretic ambiguity and wide differences of definitions. This paper tries to re-define the concept of alertness from a perspective of information processing in terms of accumulation, transformation, and selection of opportunity-relevant information. It raises an assumption that alertness precedes innovation, while innovation plays a role of intermediary variable to breed business development of new products and services. During the empirical studies, data is collected in the two countries with different cultural backgrounds, and the findings of the hierarchical regression analysis give support to the hypotheses. The contribution of the paper is mainly to the definition and measurement of alertness in entrepreneurship theory. It also discusses the intermediary function of technical innovation in entrepreneurial alertness and in new product/service development.