Heat flow is the basis data for gas hydrate reserves estimation and the oil and gas resource evaluation. The existing heat flow data measured in the South China Sea are huge but the data distribution is uneven. In order to understand the geothermal feature of the Beikang basin, this study mapped the distribution of hot flow in the Beikang basin using the measured heat flow data and previous research results. According to the characteristics of heat flow and geothermal gradient，the formation mechanism of heat flow anomaly zone in the northwest of the basin was discussed. The regional geology structure was used to analyze the characteristics of heat flow and geothermal gradient of Beikang basin and their main influence factors. The main controlling factors of heat flow distribution were briefly analyzed with the regional geological tectonic background. Statistics results show that: Heat flow varies from 430 to 1150 mW/m2 with an average value of 768±217 mW/m2， meanwhile the geothermal gradient ranges from 490 to 1331 ℃/km with the mean of 822±224 ℃/km. Heat flow is generally high, characterized by higher in the south and west than in the east， with the lowest in the southeast. And there is distinct heat flow anomalous zone in the northwestern basin. Further analysis shows: (1) Heat flow anomaly in district B is mainly influenced by the burial depth and/or thickness of high conductive layers in the crust, and districts A and C are caused by the hydrothermal circulation of seafloor fluidseep system. It can be inferred that district A should be recharge area and district C be the discharge area; (2) Heat flow distribution of the basin is obviously controlled by tectonic, with northwest and south controlled by Tinjar fault and southeast by continentocean boundary and ancient subduction zone. The distribution feature high in west and low in east was likely related to three rapid sedimentation events，but the regional high heat flow is due to the stretching of the basin. It is of great significance to the research of hydrocarbon and gas hydrate.