Abstract: 【Objective】The aim to the study is to explore the spatial and temporal distribution characteristics regularities of wheat grain quality and impaction factors.【Method】The Jimai 22 was selected because it was cultivated for long time and a wide range in China. And then by using geographical information systems (GIS) to select the optimal model, wheat grain quality spatial distribution of 6 provinces were drawn from 2010 to 2015. The key factors should be screened in water, temperature, light, longitude and latitude with correlation analysis and stepwise regression analysis during kernel formation stage.【Result】There were distinct differences in wheat grain quality around difference years and wheat production areas. The coefficient variation of wheat quality was the grain protein content＞wheat hardness＞test weight. The general spatial distribution trend of wheat hardness was low in the Northeast and high in the Southwest, and then the hardness was decreased year by year in the 6 years. Meanwhile, the spatial distributions of wheat hardness were different in those years, which were from west towards east, north to south and inner side towards outer side. In most years, the wheat hardness of strong gluten wheat region in northern part of North China (Ⅰ) and strong-medium gluten wheat region of Northern Huang-Huai Region (Ⅱ) was better than that of medium gluten wheat region of Southern Huang-Huai Region (Ⅲ). The wheat hardness was significant negative correlation with total rainfall at filling stage, total rainfall at maturity stage, mean light hours at maturity stage and latitude, moreover total rainfall at filling stage and latitude were main factors. The overall spatial distribution trend of test weight was low in Northeast and high in Southwest in those years. The test weight showed a slowly increasing trend year by year, but the test weight of 2013 was below to other years. While the wheat weight of westward and center in the Ⅱ was better than other regions. The test weight had the significant positive correlation with diurnal temperature range at maturity stage, mean temperature at maturity stage, ≥10℃ effective cumulative temperature at maturity stage and diurnal temperature range at filling stage, meanwhile diurnal temperature range at maturity stage was the main factor. The general spatial distribution trend of the grain protein content was high in Northeast and low in Southwest in the 6 years. The grain protein content had downward trend with those passing years. Most of years, the distribution of the protein content was zonal, which in the north area was integrally higher than south with the main factor latitude.【Conclusion】The main factors affecting the spatial and temporal distribution characteristics of kernel quality were total rainfall at filling stage, diurnal temperature range at maturity stage and latitude. The wheat hardness showed a decreasing trend for the increasing of total rainfall at filling stage year by year. And then the spatial distributions of wheat hardness were manifold, because of irregular change with total rainfall at filling stage and different latitude. Due to change of diurnal temperature range at maturity stage, the spatial distributions of wheat weight had a slowly increasing, and the test weight had change at different region year by year. The grain protein content had increasing trend for the rising of latitude, which had basically consistent distributions in most year. The junction area of Hebei province, Shandong province and Henan province with lower total rainfall at filling stage and higher diurnal temperature range at maturity stage, should be conducive to improving grain quality of wheat, where belong to strong gluten wheat and medium gluten wheat producing areas in Huang-Huai Northern region.

Key words: wheat, GIS, grain quality, spatial distribution, factor