HF radar backscatter from the ocean surface shows nonlinearities and time variation of its spectrum.However

the spectrum analysis method cannot reflect the evolution of the HF backscatter in time domain.In this paper

the chaotic dynamic approach is used to analyze the chaotic characteristics of the HF backscatter

and based on the observed data

it is concluded for the first time that the HF radar backscatter from the ocean surface possesses some nature of chaotic process.This conclusion will be of much significance in the target detection and ocean sensing of HF radar.