In recent years, the field of Second Language Acquisition has been witnessingstrong interests in the role of formal instruction in second language development. Asubstantial amount of empirical and theoretical research indicates that certain degree ofattention to form incorporated into primarily meaning-focused context can push thedevelopment of interlanguage system and thereby facilitate language acquisition. Butbow to achieve the aim remains an unexplored but fertile area. Based on theinformation-processing model of language learning, the present paper is intended toexplore the effects of task complexity, task difficulty and proficiency level on attentionto form and the interactions between them. The results indicate that they all have strongimpasts on attention to form. It is implied that attention to form can be generated andaltered by manipulating task complexity and task difficulty, which holds out the promiseof striking a balance between meaning and form in language acquisition. Theimplications for material and syllabus design and teaching practice are also suggested.