User-centered design (UCD) has become an important concept in Human-Computer Interaction (HCI) and other disciplines. While there is abundant UCD research, keyword analysis research has been less studied even though keywords are important for achieving better understanding of UCD. Therefore, this study provides keywords network a visual analysis of UCD articles published between 2009 and 2018 to answer the following questions: (1) What UCD-related keywords have been studied and in which disciplines? and (2) How have keywords been connected to on another? The study analyzed 304 keywords articles from IEEE, ACM, and ScienceDirect that included "UCD" in their titles. It utilized Gephi 0.9.2 to visualize keyword frequencies, relationships, and authors' disciplines. The findings presented that the five most frequently mentioned keywords regarding UCD were "usability," "HCI," "User Experiences," "User-Centered," and "User Interfaces". The top five most identified disciplines in the UCD articles were Computer Science, Design, Engineering, Education, and Psychology. In visualizing this data, we created a keyword hierarchy with various sizes of texts and circles, and we denoted various relationship levels between keywords by different weights of edges. This visualization of the selected 43 keywords shows a clear relationship between keywords in which UCD is strongly related to usability, UX, user-centered, HCI, Persona, prototype, interaction design, interface design, assistive technology, design thinking. The findings can be valuable in understanding the current UCD research mainstream for researchers and designers pursuing interdisciplinary approaches.