Patents are generally regarded as important indicators of a firm's technical capabilities. We can interpret a firm's technological development path by analyzing its patent portfolio, and the development path can explore the core technological competence (CTC) of the firm. The topic of building technological competence has attracted considerable attention in recent research by management scholars, but has not sparked much empirical analysis. Time and effort invested in the R&D of building CTC is huge, so we can analyze a patent portfolio to explore the strategic intentions of a firm. Based on the premise of strategic controllability, rather than patent citation data, this study relied on patent family members and claiming of priority patents to examine the patent portfolio of a firm, empirically validating the development of its CTCs. A company may develop a core patent portfolio of its technological competencies by filing patent applications and claiming priority. In addition, our results facilitate the prediction of a firm's future R&D direction from its patent portfolio.