Context-aware ubiquitous learning (u-learning) is an innovative approach that integrates wireless, mobile, and context-awareness technologies to detect the situation of learners in the real world and provide adaptive support or guidance accordingly. In this paper, a context-aware u-learning environment is developed for guiding inexperienced researchers to practice single-crystal X-ray diffraction operations. Experimental results showed that the benefits of this innovative approach are that it is "systematic", "authentic", and "economical", which implies the potential of applying it to complex science experiments, such as physics, chemistry or biotechnology experiments, for graduate and PhD students in colleges, or research workers in research institutes. (Contains 4 tables and 5 figures.)