早些年的观测研究证明恒星形成发生于巨分子云中的致密团块（核）中，而近年来的研究显示，巨分子云的致密气体以纤维结构的形式存在，大部分致密团块（核）都处在纤维结构中。我们将从巨分子云的角度出发，系统地研究巨分子云中纤维结构、致密团块（核）的性质和演化、它们之间的关系、它们与巨分子云整体性质的关系，探讨引力和湍动在分子云演化中的作用。我们选取15个巨分子云，将巨分子云中的纤维结构按照密度大小划分为“主干”、“枝干”和“末梢”三种类型，研究（1）三种密度纤维结构的形态、物理化学性质、动力学，各密度纤维结构之间的关系；（2）三种密度纤维结构中致密团块（核）的物理化学性质与演化状态，以及它们与纤维结构的关系。（3）纤维结构中致密团块（核）的恒星形成反馈作用对纤维结构及整个分子云的影响。

Previous works have proven that star formation takes place in the dense cold clumps (cores) in giant molecular cloud (GMC). Recent studies with Herschel data suggest that the dense gas in GMC exist in filaments, in which most massive dense clumps (cores) embedded. We noted that past observation studies toward GMCs usually focus on GMC, or filaments or clumps (cores). We will select 15 giant molecular clouds, and classify the filaments in GMC into three types by their density. Then study the physical and chemical properties of three types of filaments, the physical and chemical properties of clumps (cores) in the filaments, how GMC properties are determined by the evolution of filament and clumps (cores). We try to understand the relation between GMC, filaments and clumps (cores), explore the contribution of gravity and turbulence in GMC evolution and star formation.