The current study examined the influences of SRL prompts provided in three different phases (i.e., forethought, performance, and self-reflection) on college students' learning outcome and SRL levels during video-based learning. Fifty-eight participants were randomly assigned into one of the four conditions: 1) SRL prompts at the forethought phase; 2) SRL prompts at the performance phase; 3) SRL prompts at the self-reflection phase; 4) no SRL prompts in any phase. Participants responded to a questionnaire assessing their self-regulated learning levels and learning outcome after the video. SRL levels were also inferred by learners' behavior of pausing and rewinding during video-watching. Results indicated that participants who received SRL prompts at the performance phase achieved better learning outcomes than those receiving no prompts.