Abstract: In recent years,the research of urban land ecological security problems has become an important topic in land ecological research.The evaluation and prediction of regional land ecological security of a city is a prerequisite to solve the land ecological security issues of the city.From the perspective of human society,this paper embarked on time series analysis and the land ecological security evaluation system was constructed based on the "nature-society-economy synergetic model",using the entropy weight method and comprehensive index method.The weight of each evaluation index was obtained and the comprehensive value of land ecological security was calculated to evaluate and forecast the status of urban land ecological security and the driving factors of land ecological security in Harbin City,Heilongjiang Province,China.The countermeasures to strengthen the land ecological security of the city were proposed.The research results show as follows:(1) The land ecological security value of Harbin City was increased from 0.759 9 in 2004 to 0.890 4 in 2016,which indicated the dynamic change process following a pattern of "Sensitive level-Good level-Safe". (2) The land ecological security of Harbin City will be in the Good level in the next few years and maintain a good development trend. (3) The main influence factors of land ecological security in Harbin City include the land use structure,urbanization rate,population density and the amount of fertilizer applied to agriculture.

Key words: land ecological security, time series evolution prediction, comprehensive index method, Harbin City