Building a theory of real-time classroom formative assessment ( FA) is not only needed for the research and prac- tice of FA ，but is of critical value for the improvement of classroom foreign language teaching in China． Based on formative as- sessment literature from home and abroad ，this paper discusses the definition and characteristics of real-time FA ，reviews related empirical studies ，and points out the weaknesses in its current research． In order to build a real-time FA theory that is both situ- ated in and applicable to the foreign language teaching context in China ，the paper proposes three suggestions : ( 1) starting with the front-line classroom practices ; ( 2) focusing on the learning objectives in classroom ; and ( 3) putting the “contingencies ”be- tween the real-time FA procedures at a central place．