In this paper, we consider that temporal quantity behind ‘的’, which was used in the construction “V+了+T+的+NP”, and explores the interchange between temporal quantity and subsyance quantity with the case “V+了+T+的 +NP”, in witch ‘T’ means interchange between quantity subcategories. This paper discusses the difference between the presence and absence of ‘的’ between temporal complement and purpose, which is often confused in Chinese classroom classes, and examines what differences are there when there is “我學了三年漢語”, “我學了三年的漢語” and what cognitive effects are when there is “我學了三年的漢語”. By introducing the principles of “figure and ground,” “bounded and unbounded” and “substance quantity”, we demonstrated why the “T” can represent longer time when there is “V+了+T+的+NP”. In Chapter 2, we examine the structural characteristics of “V+了+T+的 +NP” to examine the syntactic status of ‘的’ and the syntactic status of ‘T’. In Chapter 3, we introduced the theory of “figure and ground” organization, “bounded and unbounded” organization and “substance quantity” in terms of cognitive. Finally, the cognitive function of “V+了+T+NP(我學了三年漢語)” is an object quantity representing the actual time, but “V+了+T+的+NP(我學了三年 的漢語)” with is a longer time than the exaggerated subjectivity. This study on Cognitive Function of Temporal Quantity Complement behind “的” in Modern Chinese, which can not be considered in depth by the existing syntactic analysis, through various analysis of ‘syntactic, pragmatic, and cognitive’ aspects, and expects to see the difference between “V+了+T+NP” and “V+了+T+的+NP”.