By comparing and analyzing the observed data of meteorological and botanical characteristics during the whole growth period of walnut in Longnan mountainous areas from 2012 to 2015, we found that the critical period of walnut growth and the meteorological factors that had the most significant correlation with the growth of walnut were the annual mean temperature, the annual precipitation, the average minimum temperature in April and the average temperature in July, based on which, we set up a zoning indexes system more suitable for the practical ecological climate suitability of walnut in Longnan mountainous areas, and made a zoning map about climate suitability of fine walnut planting based on GIS. The results showed that: the most suitable planting areas for walnut in Longnan were plains, shallow mountains, hills, mountains at the altitude ranging from 1000 m to 1600 m in Kangxian, most regions of Chengxian, central and southern Huixian, southern Wudu, Bailongjiang river basin, southern Wenxian and regions along Baishuijiang river; and the suitable areas for walnut planting were valleys at 900-1000 m altitude and semi-mountainous areas at 1600-1800 m altitude in Kangxian, Chengxian and northern Huixian, Lixian, central and southern Xihe, most parts of Liangdang, certral Tanchang, central Wudu, Bailongjiang river basin, central Wenxian, Baishuijiang river basin and other places. The results provide a basis for guiding the scientific planning, rational distribution, making full use of climate resources to develop walnut industry and preventing and mitigating the loss of meteorological disasters in Longnan mountainous area.