在二语研究领域，教师一直在寻找一种能使形式和意义达到平衡的教学方法。任务型教学正是以追求语言学习的准确性、流利性和复杂性为目标 (Skehan,1996)，因而被认为是实现语言表达的形式和意义平衡发展的有效途径。近年来，随着任务型教学的不断发展，以及对平衡语言表达形式和意义教学理念的不断探索，二语学习者在完成任务过程中语言表达的准确性、流利性和复杂性成为研究的热点话题。大量的研究都揭示了：由于注意力资源的有限性，学习者很难同时兼顾到语言表达的形式和意义，因而准确性、流利性和复杂性之间就会出现“竞争效应”(Foster & Skehan, 1996; Yuan & Ellis, 2003)。然而，构思是一种能够减轻认知负担、弥补注意力资源不足、缓解语言形式和意义竞争的重要方式 (Hayes & Nash, 1996)。本研究旨在探究不同的构思条件对高三学生记叙文写作准确性的影响。本研究选取了87名高三学生作为被试，按照不同的构思条件，把被试分为三组（任务前构思组、任务中构思组、无构思的控制组），并要求各组被试基于六幅图片完成一篇记叙文写作。本研究对写作准确性的测量采用了无错误小句比和正确动词比相结合的方式。研究结果显示：与无构思条件相比，任务中构思条件不仅促进了被试写作中小句表达的准确性，而且提高了动词表达的准确性；任务前构思条件提高了被试作文中小句表达的准确性，对作文中动词表达的准确性没有显著影响。总的来说，构思能够提高高三学生记叙文写作的准确性，但是任务前构思和任务中构思对学生记叙文写作准确性的影响并没显著性差异。该研究为二语写作教学提供了可靠的实证依据，也对高中生记叙文写作准确性的提高有一定的启示。

In the field of SLA, foreign language teachers were working for exploration of means to achieve balanced development of linguistic meaning and form. Task-based language teaching (TBLT) is believed an effective way achieving the balance between linguistic meaning and form, for it concentrates on three aspects of language learning: accuracy, fluency and complexity. In recent years, with the development of TBLT and the exploration of means to achieve balanced development of linguistic meaning and form, the research on investigating these three aspects of L2 learners’ task performance has become a heated topic. However, lots of research has showed that it’s difficult for learners to notice all aspects of language during task performance for the limited processing capacity (Foster & Skehan, 1996; Yuan & Ellis, 2003). Thereby, there is a competition for attention resources among fluency, accuracy and complexity and thus “trade-off effects” comes. However, planning is of great significance in regulating learners’ cognitive load, compensating for the limited attention resources and relieving the competition between meaning and form (Hayes & Nash, 1996).This study sets out to investigate the effects of strategic planning and on-line planning on senior high Grade Three students’ L2 written accuracy. Eighty-seven students were divided into three groups according to different planning conditions：pre-task planning (PTP), on-line planning (OLP) and no planning (NP). They were asked to perform a narrative task based on a series of six pictures. The accuracy was measured by counting the number of error-free clauses and accurately used verbs. The results of this study indicated that both planning conditions can promote L2 learners’ writing accuracy in comparison to NP group. To be specific, OLP lead to more accuracy in terms of both error-free clauses and accurately used verbs, while PTP lead to accuracy only in terms of error-free clauses. The results also revealed that there is no significant difference on the effect of accuracy between OLP and PTP in terms of both error-free clauses and accurately used verbs. The present study not only provides empirical evidence for second language writing teaching, but also might be helpful to improve the accuracy of Senior High students’ narrative writing.