Biogenic volatile organic compounds (BVOCs) are produced and emitted by higher plants. Terpenoids such as isoprene and monoterpenes are major compounds among BVOCs. They are highly reactive in the atmosphere and produce photochemical oxidants and secondary organic aerosols. In East Asia, efforts to measure BVOC flux above forests have not been intensively conducted, but some measurement results are published in international journals. Here I introduce BVOC flux measurements in some sites of Japan. The results revealed that storage of BVOCs, in particular during the night period, is greater than that of CO2, and that factors affecting BVOC fluxes include leaf wetness, wind stimulus to trees and turbulent mixing within and above forests. The highest flux was observed in summer for isoprene emission from Quercus serrate forests and the flux value corresponded to 40 nmol m-2s-1 or 9 mg(C) m-2h-1.