The growth and response of Gracilaria lemaneiformis to Cadmium stress in different cultivation conditions were studied, the effects of physiological and biochemical characteristics of G. lemaneiformis were explored while appending phosphate or ethylenediaminetetra-acetic acid (EDTA) into the cultured medium. The results showed that the growth of G. lemaneiformis was inhabited gradually with the increase of the content of Cadmium, the contents of phycoerythrin, Chlorophyll and soluble protein decreased, the activity of peroxidase increased at first reached the maximum value at 4.5 mg/L of Cadmium, and then dropped. While appending phosphate or EDTA into different cultured medium, the growth of G. lemaneiformis, the contents of Chlorophyll and soluble protein increased and dropped gradually with the increase of the content of Cadmium, the activity of peroxidase increased during the initial days and decreased with the prolong of time (>6 days). All results indicated that the resistance of G. lemaneiformis to Cadmium stress in low content environment was strong, the poisons of Cadmium was restricted to the factors of time and its concentration; meanwhile, phosphate and EDTA could benefit G. lemaneiformis to resist Cadmium stress to some degree.
