Abstract: The expression of ornamental characteristics of mature pot-cultivated Rhdodendron depends on the vigorous growth of plantlet and the selection on container size is a basic aspect in commercial cultivation. The elevated container sizes including C1（140 mL，6.5 cm × 6.5 cm），C2（350 mL，10 cm × 10 cm），C3（850 mL，13 cm × 12 cm），C4（1 400 mL，15 cm × 13 cm）and C5（2 850 mL，18 cm × 16 cm）were used in our experiment. The results showed that：（1）Responses to the container volume gradients were sensitively induced in biomass，growth dynamics of plant height and leaf numbers.Positive relations between physiological and morphological traits and the container sizes were presented across 140–1 400 mL（C1–C4）and the outstanding growth occurred in C4（1 400 mL）；（2）Light compensation point of photosynthesis was decreased in larger containers to accumulate more photoassimilates in partly shading condition；（3）Construction efficiency of structural and functional organs were promoted by elevated container size from 140 mL to 1 400 mL（C1–C4）；（4）Coordinative increase in biomass happened on overground and underground organs at individual level when cultivated in size-elevated containers and the allocation fraction did not be affected by the container sizes.

Key words: Rhododendron, container, biomass, photosynthesis