Experimental study on the molecular arrangement of n-hexadecane liquid was carried out in a lubricating point contact area at the nanoscale.A measurement system was developed using the techniques of polarized Raman spectroscopy and relative optical interference intensity.The molecular arrangement and the origin were studied under different lubricating states.The results indicate that the molecules in the static nhexadecane film lying parallel to the solid surfaces and the molecular orientation is random in plane.Hexadecane molecules show a similar molecular arrangement as static condition when the rolling speed is low.When the rolling speed is high,the spectral results show that the molecular orientation is disordered like bulk liquid.Hexadecane molecules are organized into a shearinduced orientation under thin film lubrication state.