Chodatodesmus mucranulatus, which is green algae with a single cell, has been used in order to determine the toxicity and characterization of the (ZnO-TiO2)(NCM.) The algal cells were exposed to (ZnO-TiO2)(NCM) for 72 hours in order to evaluate the photosynthetic activity, bioaccumulation and reactive oxygen species (ROS). The chlorophyll (Chl) an amount increased generally in the control group and treated groups depending on the exposure concentration and varying-time. The Chl b amount showed a constant increase with all treated groups of the (ZnO-TiO2)(NCM) depending on the exposure time-varying. The amount of carotenoid in the groups exposed to (ZnO-TiO2)(NCM) was considerably reduced and could not be calculated. There are very important differences between the treated groups and control groups in (ZnO-TiO2)(NCM) in 72 hours exposure of Chodatodesmus mucranulatus in terms of ROS activity (p<0.01). There is a difference at an important level between treated groups of Zn particles and Ti particles (P<0.01).