This study attempted to examine the patterns of motivational factors and their interplay involved in EFL learning through the lens of self-regulated learning. 285 grade-one senior high students from three Chinese middle schools completed a questionnaire which was designed to assess motivation (mastery goal, task value, and self-efficacy) and self-regulated learning (cognitive and meta-cognitive strategy use) in classroom context. The results of conditional process modeling of the data show that mastery goal was a positive predictor of task value and self-regulated learning effort, and that task value positively mediated the relationship between mastery goal and self-regulation. In addition, the current study provided evidence that was partially against the general assumption showing that self-efficacy belief exerted a negative moderator effect on the mastery goal, task value, and self-regulated learning relation. The findings have implications for second language teaching and learning. It is suggested that due care be exercised in designing and selecting EFL learning tasks and materials so as for students to consider them as with high value in terms of interest, importance, and usefulness; educators should treat the issue of self-efficacy with subtlety to reduce the possible debilitating effects on learners.