Quantitative trait loci (QTLs) for chlorophyll content of a rice leaf were mapped on to the molecular marker linkage map of a double-haploid (DH) population derived from a cross between two rice varieties ’IR64’ and ’Azucena’ in both nutrient solution and soil culture experiments to detect rice nitrogen nutrition status under low N stress. A chlorophyll meter was used to measure the soil plant analysis development (SPAD) value of the topmost fully expanded leaf as the index of chlorophyll content that expressed nitrogen status in rice plants. Totally 3 QTLs for SPAD values, two on chromosome 3 located at interval RG179-CDO337 and RG348-RZ329, respectively, and one on chromosome 10 at interval RZ500-RG134, were detected under stressed conditions of low N in the soil and/or nutrient solution culture experiments. One QTL located at interval RG179-CDO337 on chromosome 3 associated with a relative change in SPAD value from a high N level to a low N level in the soil culture experiment was also detected. Base Quantitative trait loci (QTLs) for chlorophyll content of a rice leaf were mapped on to the molecular marker linkage map of a double-haploid (DH) population derived from a cross between two rice varieties ’IR64’ and ’Azucena’ in both nutrient solution and soil culture experiments to detect rice nitrogen nutrition status under low N stress. A chlorophyll meter was used to measure the soil plant analysis development (SPAD) value of the topmost fully expanded leaf as the index of chlorophyll content that expressed nitrogen status in rice plants . Totally 3 QTLs for SPAD values, two on chromosome 3 located at interval RG179-CDO337 and RG348-RZ329, respectively, and one on chromosome 10 at interval RZ500-RG134, were detected under stressed conditions of low N in the soil and / or nutrient solution culture experiments. One QTL located at interval RG179-CDO337 on chromosome 3 associated with a relative change in SPAD value from a high N level to a low N level in the soil culture experiment was a lso detected. Base