Near infrared spectroscopy (NIRS) is nondestructive, efficient,fast,and well repeatable measuring tool for fruit′s quality inspecting.It′s suitable for on-site,on-lime inspection and analysis. It can play an important role in heighten fruit quality and production automation.Principle of NIRS and system structure of INRS is presented in the paper.Operation flow and data processing method are also introduced.Progress of INRS on-line detection is reviewed.Existing problems and developing prospect of INRS are pointed out.