Abstract: In order to solve problem of header profiling in fresh corn harvester which reaping both corn stalk and spike, an adaptive profiling system for header of fresh corn harvester was developed based on principle of ultrasonic ranging．In this system, ultrasonic ranging sensor was installed in the front end of header divider, which was used to detect height difference between header divider and ground in real time．Height difference signal was transmitted to central control terminal of corn harvester, which issued corresponding adjustment instruction, controlled header adjusting hydraulic system to adjust header height, and realized adaptive profiling of corn harvester's header during operation．The 190 kW four-line all-harvesting fresh food corn harvester was used as a prototype, and adaptive profiling system of header was carried out to verify profiling system．Average operating speed of corn harvester was 4 km/h, rotation speed of cutting table was 400 r/min, and stubble height was from 90 mm to110 mm．Test results showed that in whole process of 8 hours of cumulative operation, header adjustment was stable and there was no contact with the ground．Experimental results verified effectiveness of header adaptive profiling system．