Abstract: This paper dealt with the effects of Pb²⁺,Cd²⁺ and their combined pollution on the contents of chlorophyll,potassium and calcium in Thuidium cymbifolium. The results showed that except at 0.1 mg Cd²⁺·L^-1,the chlorophyll content decreased with increasing Pb²⁺ and Cd²⁺ concentrations,which was 18% of the control at 100 mg Cd²⁺·L^-1,and decreased by 48.6% at 200 mg Pb²⁺·L^-1.The potassium and calcium contents also decreased with increasing pollutants concentrations,being decreased by 61.1% at 100 mg Cd²⁺·L^-1. Cd²⁺ had a stronger toxicity than Pb²⁺,and the toxicity of their combined pollution was stronger than that of each pollutant.Pb²⁺ could increase the toxicity of Cd²⁺.

Key words: Yellow soil, Application of P fertilizer, Changes of soil P pool, P concentration in runoff