<p>Amazon rainforests and soils contain large amounts of carbon, which is under pressure from ongoing climate and land use change in the Amazon basin. It is estimated that methane (CH<sub>4</sub>), an important greenhouse gas, is largely released from the flooded wetlands of the Amazon, but the trends and balances of CH<sub>4 </sub>in the Amazon rainforest are not yet well understood. In addition, the change in atmospheric CH<sub>4</sub> concentration is strongly associated with a change in carbon monoxide (CO) concentration, often caused by the human-induced combustion of biomass that usually peaks during dry season. Understanding the long-term fluctuations in the fluxes of greenhouse gases in the Amazon rainforest is essential for improving our understanding of the carbon balance of the Amazon rainforest.</p><p>Since March 2012, we have continuously measured atmospheric CO<sub>2</sub>/CH<sub>4</sub>/CO concentrations at five levels (79, 53, 38, 24, and 4 m a.g.l.) using two wavelength-scanned cavity ring-down spectroscopy analyzers (G1301 and G1302, Picarro Inc., USA), which are automatically calibrated on site every day. In addition, we measured the CO<sub>2</sub> flux by the eddy covariance method at the same tower. We estimated the CO<sub>2</sub>/CH<sub>4</sub>/CO fluxes by combining the vertical profile of the CO<sub>2</sub>/CH<sub>4</sub>/CO concentrations with the flux gradient method. Our results generally show no major difference in CO<sub>2</sub> flux between the wet and dry seasons except for year 2017, when an elevated CO<sub>2</sub> uptake was documented during the dry season despite the lowest precipitation between 2014 and 2018. The CH<sub>4</sub> flux showed the largest CH<sub>4</sub> emission during the dry season in year 2016. Further results will be analyzed and discussed in the presentation.</p>