The patch alkali soils (PAS) in the Xuhuai district of jiangsu Province have developedupon the loess alluvial deposit,including three types,i.e,salinized yellow fluvo-aquic soil(SYFAS),alkalized yellow fluvo-aquic soil(AYFAS),and slksli-salinized yellow fluvo-aquic soil (ASYFAS).The salt and alkali of the PAS are centered at the surface soil layer and distributed sporadically,and the saline-alkali properties are complicated.There exists some connection between each of the three types of PAS.Forty samples of surface PAS.and 40 samples of corresponding groundwater were collected.The development of the types of PAS and groundwater and the relationships between the PAS types and their groundwater were analysed.The results are as follows.① The Na+,Cl-,SO4(2-)contents and SAR decreased significantly while Ca% and(HCO3+CO3)% increased generally during the desalinization Process.The salinization type varied from Na-Cl·SO4·Cl or Na-SO4·Cl to Na-HCO3·Cl·SO4 toCa-HCO3,consequently, the development of the PAS might be from SYFAS or ASYFAS to AYFAS,and finally to non-ASYFAS.The pH value was correlated with RSC andtotal alkalinity,and indirectly correlated with salt content.② The Cl- and Na+ contents and SAR fell while Ca% and(HCO3+CO3)% rose during the groundwater dilution Process,and the hydro-chemical type changed from Na·Mg-Cl·HCO3 to Na·Mg·Ca-HCO3 to Ca·HCO3 ③ The salinity of the surface soil did not directly correlated to the mineralization degree of groundwater,while the saline chemistry type was related to the hydro-chemistry type to some extent. Only SYFAS grew on the groundwater of Na·Mg-Cl·HCO3,and all of thethree types of PAS could occur upon the groundwater of Na·Mg-HCO3·Cl.