This paper reports on quantitative evaluation of influence of dopamine neurons on the flight locomotion of a fruit fly (Drosophila menanogaster). The aerodynamic force was measured by MEMS triaxial forcesensor. We compared the aerodynamic force of the genetically modified flies whose dopamine neurons (DDCII) are functionally blocked with that of the wild type ones. The peak aerodynamic force generated by wild type flies was controlled smoothly. By contrast, the peak aerodynamic force generated by genetically modified flies showed rough fluctuation. The Peak variability of the wild type flies and genetically modified flies were 0.06 ± 0.04 and 0.18 ± 0.14 [-] (Average ± S.D.), respectively. The result indicated that the DDCII-expressing dopamine neurons were necessary to control their flapping flight.