The popularity of mobile devices has encouraged the advance of ubiquitous learning, in which students are situated in a real-world learning environment with support from the digital world via the use of mobile, wireless communications, or even sensing technologies. Most of the ubiquitous learning systems are implemented with high-cost sensing devices for detecting the locations or behaviours of learners; moreover, these systems mainly focus on providing learning guidance or learning materials, while facilities for supporting mutual help among students are usually ignored. In this study, we propose a context-aware ubiquitous learning platform (CULP) which uses low-cost cell phones with embedded cameras and Internet service to support ubiquitous learning. CULP is able to provide instant support for learners in the ubiquitous learning activity; that is, learners can receive help from the right people via the hints given by the learning system when they encounter problems during their learning activities. The experimental results of a Personal Computer-Assembling course show that, with the assistance of the new learning platform, both the learning efficiency and the learning achievement of the students were significantly improved.