To examine water consumption rules in Eucalyptus macrophylla and Pinus elliottii×P. caribaea and to provide guidance for tree species selection, cultivation and tending of regional plantation, sap flow of plantation grown, E. urophylla and Pinus elliottii×P. caribaea were continuously measured using the Thermal dissipation sap flow velocity probe technology and the meteorological factors were continuously monitored and measured simultaneously to establish a sap flow rate model with meteorological factors. The diurnal variation and seasonal variation of transpiration water consumption of E. urophylla and Pinus elliottii×P. caribaea in the Leizhou Peninsula were analyzed. Results showed that diurnal variations of sap flow of both E. urophylla and Pinus elliottii×P. caribaea displayed typical single-peaked curves. The average monthly flow rate was different and significant difference was found during the rainy season and drought. The peak sap flow of E. urophylla in the rainy season (0.127 cm/min) and dry season (0.096 cm/min) were 1.30 times and 1.57 times higher than that of Pinus elliottii×P. caribaea, respectively. The average daily flow rate of E. urophylla in the rainy season (0.045 cm/min) and dry season (0.033 cm/min) were 1.27 times and 1.54 times higher than that of Pinus elliottii×P. caribaea, respectively. There was no significant difference between the start-up time and the rapid decline time of the two species in the rainy season. But the E. urophylla in the dry season increased by about 1-1.5 hours in advance and started to decline rapidly 0.5-1 hour later than that of Pinus elliottii×P. caribaea. The main meteorological factors affecting the sapwood flow rate of the two species are the same. The average single plant daily water consumption of E. urophylla plantation was 12.79 L/d, which was 1.33 times higher than that of Pinus elliottii×P. caribaea. The stand transpiration water consumption of E. urophylla (582.16 mm) and Pinus elliottii×P. caribaea (483.24 mm) accounted for 34.2% and 28.4% of the annual rainfall, respectively, and the Stand transpiration water consumption of both tree species during the rainy season was significantly greater than that during the dry season.