Abstract: We investigated the agronomic and physiological characters of the lily bulbs．which were treated with atrazine in different growth phases before sprouting．The results showed that atrazine had different effects on the plants in different
growth phases．Comparatively，the bulbs treated before sprouting were less significantly affected except some physiological changes．The content of chlorophyll，soluble sugar content and dark respiration rate increased in bulbs of the treated plants，while net photosynthesis rate，special leaf weight and dry matter weight decreased．The result of correlative analysis showed that the content of soluble sugar was positively correlated with dark respiration rate．The increase of soluble sugar content disturbed the photosynthesis of plants to some extent．Thus，it was demoastmted that atrazine could affect the accumulation of photosynthetic products in lily plants through influencing the metabolism and transportation of sugar，and CO2 fixation in the chloroplast．

Key words: atrazine, oriental lily, herbicide, agronomic characters, physiological characters