According to the characteristics of grain production fluctuation,the influencing factors such as natural factors,technological factors,socio-economic factors and conditional of agricultural production were studied,so as to provide a theoretical method for establishing scientific and reasonable agricultural policy and ensuring food security in China. Hodick-prescott filter method was used to analyze the characteristic of grain production fluctuation in China from 1978 - 2010,grey correlation analysis and analytic hierarchy process (AHP) method were used to quantitatively analyze the influence degree of influencing factors in different fluctuation cycle. Grain production had experienced 6 fluctuation cycles from 1978 to 2010,the average time scale of fluctuation cycleswas 6 years. In different cycles,technological factors had the greatest impact on grain production fluctuation,the influence degree increased from 37.0% in 1978-1981 to 48.3% in 2006-2010,among which,the effect of irrigated area on grain production increased dramatically,while the effect of chemical fertilizer consumption was graduallyweaker. The effect of socioeconomic factors increased volatility and reached to 25.0% in 2006 - 2010. In the early 1980s,the effect of conditions for agricultural production was as important as technological factors,otherwise,the influencing degree fell down to 16.5% in 2006 - 2010,among which,the effective degree of the arable area had the biggest drops and fell down to 1.1%. Natural factors had the minimal impact on the grain production fluctuation,and grew steadily from 8.7% to 12.8%, the effective degree of which reached to 24.3% during 1985 - 1988. " Focusing on technology" by improving irrigation system and enhancing guidance of agricultural machinery has more efficiency than " relying on resource" by increasing the reserve cultivated land improving ability to cope with climate change and natural disasters. Increasing investment in water conservancy,completing the constructionin irrigated areas and drainage pumping station renovationwill be the most useful methods to ensure food security.