Abstract: As an open and complicated system，traffic system is highly nonlinear and indetexminated ．This article simulates and analyzes the traffic flow based on the theory of phase space reconstruction．By choose appropriate delayed time and embed dimension，we get a relevant associated dimension，just as the attract dimension．This article gets a fractional dimension which exceeds 2．That explain the system is a chaos system．and if we want to construct a relevant kinefic model，we must need 3 absolute variables at least．This method has a significant meaning for forecasting traffic flow．

Key words: traffic flow, phrase reconstruction, delayed time, associated dimension, chaos

摘要： 利用相空问重构法，对道路交通中的车流量进行模拟分析，在选择适当的嵌入维数和延迟时间的情况下，得 到相应的关联维度，即车流量这个时间序列的吸引子维度．得到的关联维度是个大予2的分形维，说明构成此序列 的交通系统是个混沌系统．如果要进一步构建此系统的动力学模型，至少需要3个独立的参数变量．此方法为道路 交通预测工作的顺利展开打下了一定的基础．

关键词: 交通流, 相空间重构, 延迟时间, 关联维数, 混沌