Long-term measurements of the albedo of tropical forest and ranch land have been made at three paired sites in Brazil. The mean forest albedo, 0.134, is slightly higher than the value that has generally been used in GCM deforestation simulations, while the mean ranch land albedo, 0.180, is slightly lower than the value usually used. The monthly means of daily albedo at the forest sites all have a well-defined seasonal variation that is not due to the effects of the changing solar elevation angle or to variations in cloudiness, but is correlated with the soil moisture. The albedo of the ranch land sites shows some month to month variation, but there is no clearly defined seasonal trend.