Annual Cyphomandra betacea Sendt. seedlings were used for the study of its leaf traits and stoichiometry under shade. Four different light intensities(100%, 75%, 50% and 25% NR, NR being natural light) were set up to determine leaf traits and C, N, P and K contents of C. betacea seedlings and to analyse the variability among the indicators. The results showed that leaf length, leaf area, leaf moisture content and specific leaf area were greatest under 50% NR and the C contents of leaves were greatest under 100% NR. The N, P and K contents of leaves were higher than those of stems, thick and fine roots under shade treatment. Over increasing shade, the K contents of all organs(except for thick roots ) and leaf N/P kept increasing. The leaf and fine roots C/N and C/P were smaller than those of stems and thick roots, while the stems N/P and N/K were smaller than those of leaves, thick and fine roots. Under shade treatment, the growth of C. betacea was limited by N and P, but not by K. C. betacea seedlings adapted to light changes by changing leaves N and P contenst, stems N contents and thick roots K contents. A 50% shade environment could be chosen for outdoor cultivation, extension planting in the forest and for garden applications with proper N and P fertilizer.