The evaluation of nitrogen use efficiency on low-nitrogen level and correlation coefficients among characters related to grain yield and nitrogen use efficiency were conducted by using 180 accessions of core collection of rice (Oryza sativa L．) in China．The results showed that the range of variance of straw nitrogen contain rate (SNR) and straw nitrogen absorption per plant were 0.56-1.85% and 0.04-0.61g, respectively. The range of variance of grain nitrogen contain rate (GNR) and grain nitrogen absorption per plant were 1.28-3.23% and 0.02-1.04g, respectively. The range of variance of nitrogen absorption per plant was 0.10-1.30g. The range of variance of nitrogen grain production efficiency (NGPE) was 3.85-57.52g/g. The range of variance of nitrogen plant biology production efficiency (NPBPE) was 17.56-104.02g/g. The range of variance of nitrogen harvest index (NHI) was 7.05-88.58%. There were obvious different among rice germplasms. There were no obvious different on SNR, straw nitrogen absorption (SNA), GNR, grain nitrogen absorption (GNA) and plant nitrogen absorption (PNA) between Japonica rice and Indica rice. There was no obvious different on NPBPE, even the value of indica rice were a little big than Japonica rice. There were obvious different on NGPE and NHI between Japonica rice and Indica rice. NGPE and NHI were significantly positively associated with seed setting rate, grain weight per plant and effect panicle per plant. Directly to select seed setting rate, grain weight per plant and effect panicle per plant were more effective selected higher resistance to low-nitrogen and higher nitrogen use efficiency under low-nitrogen condition.