Abstract: ‘C.humilis No.6’ and ‘C.humilis No.7’ were taken as test material, four planting densities（0.5 m×0.5 m, 0.5 m×1.0 m, 0.5 m×1.5 m, 1.0 m×1.0 m） were set up to determine the growth index（plant height, ground diameter, crown width）,leaf area（LA）,specific leaf area（SLA）,leaf dry matter content（LDMC）,chlorophyll content（SPAD） and fluorescence indexes（Fo, Fm, Fv/Fm, Fv/Fo, qN, qP, ETR）.The effects of planting density on growth and light energy utilization of C.humilis grown in organic greenhouse were studied to provide theoretical guidance for its efficient production and cultivation.The results showed that there was significant difference on growth and light energy utilization of C.humilis in different planting density, and varied by variety.The growth and utilization of light energy of ‘C.humilis No.6’ increased first and then decreased with the decrease of density.When the planting density was 0.5 m×0.5 m, the ground diameter, crown width, LA, SLA,and Fv/Fm, Fv/Fo were the smallest, and the qN value was the largest.The plant height, ground diameter and crown width of ‘C.humilis No.6’ were the largest, the LA,SLA and SPAD values were the highest when the planting density decreased to 0.5 m×1.5 m, and the ground diameter and crown width were significantly higher than those of other densities（P＜0.05）.The fluorescence parameters Fv/Fm and Fv/Fo were the highest, and qN was the lowest.However, all indexes had different degrees of decline when the planting density decreases to 1.0 m×1.0 m.The growth and utilization of light energy of ‘C.humilis No.7’ increased with the decrease of density.The ground diameter, crown width, LA,SLA and SPAD values were the lowest at 0.5 m×0.5 m, and the ETR,qP and qN values were the highest.The ground diameter, crown width, LA, Fv/Fm, Fv/Fo and ETR both were the largest, SPAD value was the highest, qN was the lowest at 1.0 m×1.0 m density.The suitable cultivation densities of ‘C.humilis No.6’ and ‘C.humilis No.7’ were 0.5 m×1.5 m and 1.0 m×1.0 m respectively under the greenhouse organic cultivation mode.The reasonable planting density should be determined according to the varieties to ensure that the plant grows well and the benefit is maximized in the production and cultivation of C.humilis in greenhouse.