Microplastic (MP) sorption and transfer of chemical contaminants has been widely reported, yet few studies have investigated combined effects of contaminant-loaded MPs on organisms. Microplastics can act as carriers of environmental chemical pollutants and pesticides. Absorption of these particles by living organisms, especially aquatic organisms, causes changes in the activity of enzymes in the antioxidant pathway and peroxidation of membrane lipids. The aim of this study was to investigate the microplastic effect of polyethylene terephthalate and abamectin pesticide alone and in combination on glutathione peroxidase ‎(GPX) ‎activity and lipid peroxidation of zebrafish. In this study, zebrafish were exposed to a concentration of abamectin (0.006) and two microplastic concentrations of polyethylene terephthalate (5 and 10) and Their combination ‎(0.006 mg L^-1 ABM‏ ‏+5‎‏ ‏mg L^-1 PET) and ‎(0.006 mg L^-1 ABM‏ ‏+10 ‏mg L^-1 PET). In this study, the activity of glutathione peroxidase and malondialdehyde (MDA) were evaluated as indicators of lipid peroxidation. Analysis of results by one-way ANOVA method and significance of Pvalue <0.05 showed that the amount of malondialdehyde in treatment (0.006 ABM)was significantly decreased compared to the control and glutathione peroxidase activity in treatment 0.006 ABM +5 PET  treatment 0.006 ABM +10 PET was significantly increased compared to the control group. Also, analysis of the results by Two-way ANOVA method showed interaction in 0.006 ABM +10 PET treatment in glutathione peroxidase enzyme and this effect was not observed in other combination treatments.