The heavy metal pollutions and environmental estrogen pollutions are two crucial environmental problems faced by human beings. In this study, with two representative substances cadmium and DDT, considering their complicated molecular mechanisms and lack of effective and sensitive monitoring assessment system, using fluorescent real-time PCR method and Tetrahymena thermophila cells as materials, we carried out research introduced as follows: The expression of metallothionein gene (MTT1) in T. thermophila treated with different concentrations of heavy metals cadmium and copper was studied, of which the results shows: MTT1 gene was more sensitive to cadmium induction compared to copper, and in a certain threshold scale (≤35.2 mol/L), raising the cadmium concentrations increased the MTT1 expression level, but made it decreased while beyond the threshold; the expression rule of MTT1 induced by both cadmium and copper was similar to that treated with cadmium only, but then the threshold down to 22 mol/L, indicating that combined toxicity of cadmium and copper in T. thermophila was synergism. When treating concentration was lower than 22 mol/L, cadmium cooperated with 244 mol/L copper greatly increased the expression level of MTT1, hence enhancing the detoxification ability of Tetrahymena. The potential molecular mechanism of combined toxicity caused by cadmium alone or with copper together was also discussed. Based on cloning and sequencing of five T. thermophila tox-genes (TtSCP-2、TtOMC、TtGST、TtCYP and NgoA), analysis were made to their structural features, function backgrounds, expression levels exposed to different concentrations of DDT and the genes’ upstream-side regulation sequences while the results suggests: The 5 genes are all related to the physiological and biochemical processes involved in cell toxicology under DDT treatment, including intracellular transportation (TtSCP-2 and TtOMC), cellular toxicity genesis under toxic substances treatment (all of the 5 genes) and xenobiotic metabolic processes (TtGST and TtCYP), which is helpful to elucidate mechanisms of cell toxicity genesis caused by environmental estrogens in Eukaryotics; the remarkable changes on their expression levels under certain DDT concentrations also indicate that these genes could be taken as important molecular marks specific responsive to DDT and environmental estrogens, thus providing theoretical and experimental bases on which the final goal aiming to a Tetrahymena monitoring and assessment system with high specificity and sensitivity could be achieved.