The effects of Zn on chlorophyll content and scavenging system of activated oxygen in leaves of rape were evaluated by cultivation experiments. The results showed that external symptoms, physiological and biochemical index and SOD activity were impacted by Zn treatments. The activity of SOD and contents of chlorophyll increased firstly in lower concentration of Zn (200 mg·kg-1), while the velocity of O2•- production and the cell membrane permeability had no marked change, and the balance of proSubscript texttective enzyme system was hold. Those may be regarded as a protecting function of plants. However, with the increase of concentration of Zn, negative effect had existed, the fronds were shorter and smaller, content of leaf pigments and the activity of SOD decreased drastically. The sensibility order of pigments to Zn stress was similarly Chlorophyll a> Chlorophyll a+b >Chlorophyll b. The velocity of O2•- production was increased sharply, the membrane penetration and electric conductivity were increased. Furthermore, the activate oxygen metabolism system of rape (Brassica Chinensis L) was destroyed. The results indicated that Zn stress affected scavenging system of activate oxygen and resulted in the balance of protective enzyme system was broken. The results also suggested that the tolerance limit of rape (Brassica Chinensis L) to zinc was 1000 mg·kg-1.