The aim of this research is to answer two research questions about a firm's disruptive innovation in a changing industrial technological environment. First, how does industrial technological environment influence a firm's extent of disruptive innovation? Second, how does a firm's disruptiveness interacted with industrial innovation environment affect firm performance? By conducting an empirical research for Taiwan's information technology firms, the results show that in a higher industrial sustaining innovation level, smaller firms are inclined to have a higher extent of disruptive innovation. More importantly, a firm's higher disruptive innovation extent can help to improve a firm's market performance particularly in a higher industrial sustaining innovation level.