Abstract: Zhuhai's Phoenix Mountain, where the forest vegetation coverage rate has reached 90%, is located just south of the tropic of cancer.The vegetation type is evergreen broadleaf forest, which represents the typical secondary forest type around cities and villages in Linnan in the south subtropical zone.A tower station for monitoring the interaction and CO₂ flux between land and atmosphere has been built in the forest land at the foot of Phoenix Mountain.In this paper, the geographical environment, instruments and basic observations of this tower station are introduced in detail.The diurnal variations of key meteorological variables on a typical clear day in the dry season are analyzed.For total and spectral radiation and their reflection radiation values, results reveal a conventional symmetric structure, with the highest values at noon.Downward longwave radiation is lower than upward longwave radiation for the forest canopy.The peak value of air temperature lags that of solar radiation.The air temperature is lower in the upper layer than in the lower layer before its maximum;and then, after decreasing precipitously from this maximum to sunset during the day, it is lower in the lower layer than in the upper layer at night.For relative humidity, the maximum occurs in the early hours of the morning and the minimum occurs in the afternoon.The air is relatively wet in the lower layer at night, and vice versa during the day.In November, Zhuhai experiences a mainly northerly-blowing monsoon.The land and sea breezes play an obvious role, with the sea breeze being strong and the land breeze weak.The sensible heat fluxes are similar to the latent heat fluxes over the forest canopy, with the latter being basically positive.The sensible heat fluxes are positive during the day and negative at night.The maximum CO₂ uptake by the forest canopy occurs in the afternoon, when the water vapor concentration is smallest.The maximum CO₂ emission by the forest canopy occurs in the morning, after sunrise, when the CO₂ concentration and air density are largest.The soil moisture content is almost constant in the same layer under tall and dense forest.The amplitudes of surface soil temperatures become smaller with soil depth.The soil heat flux is stronger in the afternoon and weaker in the morning.Some of the phenomena revealed in this paper should be analyzed and verified in future work as the datasets of these variables grow.