Flow field structure of stirred tank is closely related with mixing effect.To enhance mixing efficiency and reduce energy consumption of fluid mixing, it was an alternative way to control the flow field structure.With matlab software, fractal Characteristic of flow field was investigated in the eccentric air-jet stirred reactor; At the same time, Numerical simulate flow field in eccentric air jet-stirred reactor using Fluent(v.6.2.30)and its preprocessor Mixsim(v2.2.10).The objective of this study is to Relationship between various flow pattern in the reactor and its factal dimension.Results showed that the fractal dimension and flow pattern can further explain the behavior of the fluid mixing tank and provide theoretical support for design and optimize jet-stirred reactor.