Abstract: Firstly, this study used Google Earth images to visually interpret the mangrove distribution area of Techeng Island in Zhanjiang in the past 20 years. Secondly, correlation analysis, regression analysis and principal component analysis were used to quantitatively explore how mangrove distribution area in Techeng Island of Zhanjiang could be affected by air temperature, precipitation and socio-economic activities in coastal zone. The result showed that there was a positive correlation between air temperature and mangrove forest area, and a negative correlation between rainfall and mangrove forest area. There was a lag effect for the influence of air temperature in January and rainfall in dry season on mangrove forest distribution. The lag period is 3 years for the air temperature in January and 2 years for the rainfall in dry season, respectively. This results partially indicated that the effects of climate factors on mangrove distribution would continue for several years. The increase of extremely cold air temperature weather and rainfall in dry season may not be conducive to the growth, reproduction, migration and spread of mangrove plants, and even aggravate the degradation of mangroves. Moreover, total population, gross domestic product (GDP), agricultural output value, total output of aquatic products, cargo throughput, and number of tourist in the urban district of Zhanjiang were all negatively correlated with mangrove distribution area. Thus, the influence of socio-economic activities in coastal zone on mangrove forest distribution cannot be ignored.