Procrastination, as Steel (2007) reviewed, is the phenomenon that individuals voluntarily delay to start or complete an intended course of action despite expecting to be worse off for the delay. The previous studies have indicated that chronic procrastination exists in different cultural backgrounds, with about 15% ~ 20% of adults troubled. Academically, more than 40% of students admit to academic procrastination, and some may even suffer from chronic tendencies. With the rapid development of modern society, the problem of procrastination is more serious and prominent. Obviously, putting off the task irrationally not only does harm to individuals’ study, work, emotion, but also endangers mental health. However, little is known about procrastination concerning the core mechanism of origin, the critical period of its formation, and its corresponding underlying neural substrates. To fill this gap, the current study investigates the core mechanism of procrastinated decision - making which rely on the Temporal Decision Model (TDM) we outlined, and explores the developmental cognitive neural mechanism of procrastination form a behavior - environment - brain perspective, and also sheds light on how to prevent or intervene the procrastination in these critical periods. First of all, the behavioral development measurement of the study aims to use a cross-sectional design to explore the occurrence and developmental characteristics of procrastination, the critical period (sensitive period) and the relevant influence factors (including various environmental and educational variables) of procrastination formation in children with three age groups (6 ~ 8 years, 10 ~ 12 years, and 12 ~ 15 years). And we also investigates the effects or underlying mechanisms of the cognitive abilities such as self-control, long-term value evaluation, time discounting, and emotion regulation on procrastination at each age stage. Meanwhile, the time decision model of procrastination is tested and refined in the study form a developmental perspective. Secondly, on the basis of neural level, procrastination is related to functional deficits in the frontal lobe, limbic system (e.g., amygdala, hippocampus) and other brain regions. Thus, the brain development measurement of the study aims to examine the development of brain structure and brain function in children aged 6 ~ 15 years using Magnetic Resonance Imaging (MRI) multimodal imaging techniques (including task, resting, voxel-based morphometry (VBM), diffusion tensor imaging (DTI)), and functional Near-Infrared Spectroscopy (fNIRS) techniques. Based on the correlation analysis among brain structural data, functional data and behavior data, the study systematically investigates the developmental cognitive mechanisms of procrastination that are influenced by relevant influence factors, such as long-term value evaluation, delay discounting, self-control, emotion regulation and episodic future thinking. In addition, the study intends to build a behavioral - environmental - brain multilevel model for predicting the formation of procrastination in children. By integrating multimodal data on behavior, environment, and brain variables, the influence of environmental variables on procrastination through the malleability of brain structure and function is examined using the mediation analysis and structural equation model. What’s more, considering behavioral intervention for procrastination and malleability of the brain development, the study also sheds light on develop a clinical proposal for the prevention and intervention of procrastination at each critical periods according to the developmental characteristics of each age (including childhood, adolescence, and adult), mainly using intervention training methods, such as episodic future thinking, time management, and emotion regulation, and so on. To sum up, on the one hand, the current study can reap enormous scientific contributions to clarify the neurocognitive mechanism and the rules of development of procrastination; on the other hand, the study further obtain the practical significance for the prevention and intervention against procrastination behavior with exploring the effectiveness of intervention from the perspective of brain malleability.