This paper revealed the annual population fluctuations of the meadow moth (Loxostege sticticalis L.) and demonstrated the characteristics in mild occurrence years, and the effects of climate change on its occurrence in China. The time series of the meadow moth in occurrence area were analyzed by comparing differences between the severe and mild occurrence years during 1949-2012. The temporal and spatial patterns of the meadow moth in mild occurrence years were demonstrated in the northern agro-pastoral regions of China during 2006-2012, by analyzing the appearance date, lasting period and the number of counties of each development stage and generation annually. On the traceable time series of 1951-2012, the correlation between large-scale climate indices and meadow moth occurrence levels were analyzed, using annual average temperature, average temperature of January and accumulated precipitation during June-August as crucial factors in 169 weather stations with consecutive climatic data, which are located at the occurrence area of the meadow moth. The results showed that: (1) For this migratory and intermittent out-breaking pest, the frequency of mild occurrence years was higher than that of severe occurrence years in the past 62 years. It indicated that mild occurrence was dominant situation rather than severe occurrence in the long term; (2) The mild occurrence years generally characterized by late appearance date, short occurrence duration and small damaged area; (3) The large-scale climate change had significant influence on the inter-annual fluctuation of meadow moth occurrence. The increase of occurrence area was found positively correlated with increase of both annual average temperature and average temperature of January; while, negatively correlated with the accumulated precipitation from June to August during 1951-2012. In conclusion, it is essential to notice the population dynamic of meadow moth in mild occurrence year in a long-term, because it is very important for understanding long term population dynamics and the outbreak patterns. The annual occurrence area could be taken as the major index to quantitatively assess the occurrence level. Correlation analysis between occurrence area and climate factors in large-scale and long-term would be an effective methodology to examine the climatic effects on the meadow moth occurrence.