Reflection is one of the most important factors that affects learning. A good learning strategy is supposed to improve a learner's reflection level. In addition, the past studies has proved u-learning can enhance learning performance, motivation and efficiency of learners. This study integrates these into learning activity of distinguishing vegetation, let learner reflect in u-learning environment. Almost of past researches promoted learners¡¦ reflection was by text-based. However, the limit of learning activity's character and mobile device¡¦s screen, the design of text-based promotes is confined. Therefore, this study proposes a video-based reflection prompts strategies in high media richness, and the Context-Aware Reflection Prompt System (CRPS) can detect learner¡¦s location by QR Code to provide appropriate guidance, facilitating learner to observe and reflect. Further to explore effects of reflection level and satisfaction between video-based and text-based reflection prompt strategies. This study recruited 70 college students to participate in this experiment, and divide into two groups of video-based and text- based reflection prompts. The results showed that the reflection level of the video-based reflection prompt group is significantly improved than of the text-based reflection prompt group; however, there was no differences found on the satisfaction. In addition, this study further investigated the learners¡¦ opinions and perspectives toward a video-based and a text-based reflection prompt strategy, and interviewed some learners to obtain the potential factors which may affect satisfaction.