Drawing from Expectancy-Value Theory, this study explored the extent to which the interaction between learning motives for and self-efficacy in learning English as a foreign language (EFL) predicted deep language learning strategies by involving 693 undergraduates from mainland China in a survey. Stepwise multiple regression indicated that (i) as for the impact on language use strategies, the interaction was significant between self-efficacy and instrumental motives while it was insignificant between self-efficacy and intrinsic motives; (ii) as for the impact on language learning management strategies, the interactions between self-efficacy and two motives were both significant. This study develops existing language learning theories through (i) generating evidence to support the existence of the "Expectancy × Value" interaction in the context of learning EFL, and (ii) revealing the motive-specific and strategy-specific features of the interaction when deep language learning strategies are under investigation. Implications for enhancing students' deep language learning strategies are discussed.