Abstract: The method of space subarea and dynamic monitor of relative light intensity within sunlight and overcrowed canopy of the 13 years-old trees of ‘hongdeng’sweet cherry were applied to study the distributive difference of relative light intensity, yield and quality, and relationships between relative light intensity and quality. The results showed that the relative light intensity increased gradually from bottom to top, the percent proportion of ＜35% relative light intensity in volume of canopy were separately 25.23% and 52.78%. The distribution of fruit were uniform and centered on 1.5-2.5m height in the sunlight canopy., while that were difference and outer positions of the canopy in the overcrowed canopy, and the yields were 9.02 t.hm-2 and 3.53 t.hm-2 in sunlight and overcrowed canopy respectively. The regression analysis of the relationship between relative light intensity and fruit quality factors was used to obtain optimum relative light intensity values that mean fruit mass, fruit firmness, soluble solids content, titratable acid and TSS/TA were 76.52%, 46.84%, 100.00%, 41.63% and 75.77% respectively.

Key words: sweet cherry, canopy, relative light intensity, yield, quality