Abstract: Taking soil from facility cultivation parks as test materials, a two-factors randomized block experiment was conducted by different straws（no straw R0,rape straw R1 and rice straw R2）,and different forms of nitrogen fertilizers（no fertilizer N0,CO（NH₂）₂ N1 and KNO₃ N2 and controlled release urea N3） under solar greenhouse condition.Some soil nutrient indicators and their interrelationships were determined and analyzed, in order to provide reference for the soil improvement and fertilization techniques by organic combined with inorganic fertilizers under facility cultivation in Northwest China.The results showed that, 1) the soil urease activity was significantly increased after applying straw, compared with R0,soil organic matter（SOM） were increased by 10.6% and 22.4% and mineral bound organic carbon（SOC） were increased by 5.7% and 8.8% and available potassium（AK） were increased by 25.9% and 26.7% under R1 and R2 treatment.2) Compared with R0 treatment, soil nitrate nitrogen（NH₄-N）,available phosphorus（AP） and pH were decreased by 32.2%,23.6% and 1.5% under R1 treatment, and there was no significant change in R2 treatment.3) After applying different forms equal amounts nitrogen fertilizer, soil urease activity was significantly inhibited by N1 and N2 treatments, the NH₄-N content of N1 and N3 was 41.5 and 13.9 times higher than that of N0,respectively.The soil nitrate nitrogen（NO₃-N） content was significantly increased by N1,N2 and N3 treatment, and AP of N1 treatment was increased by 47.4% compared to N0.4) There was a significant positive correlation between SOM and SOC,total nitrogen, and urease activity.The NO₃-N content was significantly correlated with EC value and AK.In a conclusion, it could be seen that rapeseed straw was superior to rice straw in improving soil organic matter, urease activity, and increasing soil effective nutrients.Ordinary urea was superior to the other two nitrogen fertilizers in balancing the proportion of nitrate and ammonium nitrogen in the soil and increasing the content of available phosphorus.It was recommended to combine rapeseed straw with ordinary urea for facility soil fertilization and improvement according to the soil salinization under facility cultivation, the susceptibility to ammonia poisoning in enclosed environments, and the nutritional characteristics of horticultural crops.