The main purpose of this study was to evaluate SIM effects on tilapia in relatively low concentrations and the molecular response of tilapia under SIM exposure. Mozambique tilapia (Oreochromis mossambicus) male gonad RNA-seq under different simvastatin concentration long-term (two-month) exposure. The purpose is to understand the molecular response after simvastatin exposure in tilapia and to provide information for the aquaculture industry. The raw data is from Illumina Nextseq 500, 2 x 75bp. The analysis can investigate the transcriptome profile analysis of male gonad under two different concentrations and systemically displayed involved molecular pathways. This work will provide contribute to the practical application of tilapia as a typical aquaculture animal species in environmental risk assessment.