Abstract: 【OBJECTIVE】The objective of this investigation was to study the effects of NH4+-N/ NO3--N ratios on the yield and soluble oxalate content of spinach fresh shoot. 【METHOD】Spinach seedling was treated with different ratios of NH4+-N/ NO3--N，the yield and soluble oxalate content of spinach fresh shoot were observed after 36 days. 【RESULTS】Results showed that (1) from NH4+-N/ NO3--N ratio of 100:0 to the ratio of 0:100, spinach shoot fresh weight gradually increased with the increase of the percent of NO3--N in the total nitrogen. Spinach supplied with NO3--N as its sole nitrogen source had the highest yield; (2) with the decrease of the NH4+-N/ NO3--N ratio, the soluble oxalate content of spinach shoot gradually decreased. As the NH4+-N/ NO3--N ratio of 25:75, the soluble oxalate content was the lowest, with the ratio further smaller, the oxalate content was reversed to increase. There was a significant quadric relationship between the percent of in the total nitrogen and soluble oxalate content of spinach shoot. 【CONCLUSION】The yield of spinach was increasing with the NH4+-N/ NO3--N ratio increasing, the oxalate content was the highest when the ratio of NH4+-N/ NO3--N was 25:75