Abstract: Abstract: Based on the data of soil testing and fertilizer recommendation project, we researched and screened the formulae of spring maize special compound fertilizer in Ying County in northern Shanxi Province by the GIS (geographic information system). We followed the principles of regional nitrogen (N) amount control and timing in critical growing stage, and soil available phosphorus (P) and potassium (K) maintained at a rational level. Firstly, we collected soil testing data and "3414" field experiments data of spring maize in Ying County. The regional appropriate N application rate was 200 kg/hm2 by the fertilizer effect function method, among which 80 kg/hm2 was as base fertilizer applied before sowing while 120 kg/hm2 was as topdressing applied at large bell stage. Furthermore, we established the functional relationship between available nutrients (P and K) and relative yield, which was used to determine soil nutrient plenty-lack index of P and K. The results showed that soils were divided into low level (< 5 mg/kg), medium level (5-16 mg/kg), high level (16-26 mg/kg) and very high level (> 26 mg/kg) groups by P classification indices. As well as, on the basis of K classification indices, soils were divided into low level (< 30 mg/kg), medium level (30-105 mg/kg), high level (105-150 mg/kg) and very high level (>150 mg/kg) groups. According to spatial variability characteristics and classification indices of soil available P and K, we set up P and K recommended fertilization index system by the comprehensive utilization of the soil nutrient plenty-lack index method and the fertilizer effect function method. Based on the analytical data of 1374 soil samples, by using Kriging interpolation of GIS, we obtained the spatial variability maps of regional soil nutrient P and K. The results indicated that the spatial variability of available P and K was obvious. Because of this, the scientific management of soil available P and K and the rational use of P, K fertilizers were important for regional agricultural development. In additon, using GIS technology we also obtained the maps of regional N, P and K fertilizer recommended dosage, which showed that P fertilizer application rates of low-level, medium-level, high-level, very high-level soils were 90, 68, 45 and 30 kg/hm2, respectively, while K fertilizer application rates were 68, 45, 30 and 15 kg/hm2, respectively. The regional appropriate N application rate was 200 kg/hm2, of which 80 kg/hm2 was base fertilizer and 120 kg/hm2 was topdressing. After overlay analysis of N, P and K fertilizer recommended dosage maps by the GIS, we formed the spring maize formula figure for the county. The formula figure showed that there were 11 special fertilizer formulae with different proportion in the area, whose total nutrients were all designed to 45%. Through further screening study, we proposed 3 general regional N-P2O5-K2O formulae for spring maize in Ying County, which were 20-17-8, 17-19-9 and 21-12-12(NPK nutrient content ratios of special compound fertilizer, which total nutrient content was 45%). The areas of 3 general regional formulae followed the trend of 20-17-8 > 17-19-9 > 21-12-12. In order to evaluate 20-17-8 regional formula, we conducted the field trials. The results showed that the maize yield increased by 7.69 % with the designed regional formula in comparison with farmers' habitual practice, but the difference was not significant. The other 2 formulae needed to be verified in the future research. With all results of analyses, we find that the GIS technology is a very effective means for studying the formula of regional special compound fertilizer, which helps us learn the regional soil nutrient condition and fertilizer demand situation intuitively. All in all, soil testing and fertilization technology combined with GIS technology can promote the application and popularization of soil testing and formula fertilizing project, and provide the theoretical basis for spring maize nutrients' efficient utilization. By this way, we can improve the regional fertilization technology and promote the economy development of the area.