CRISPRs(clustered regularly interspaced short palindromic repeats) / CRISPR - associated(CAS) system has been used genome editing technology. Genome stage modification using CRISPR/CAS9 system can be used to wide research for the gene functional study and therapeutics. However, improving of CRISPR/CAS9 system in efficiency is essential for application in various fields. Here, we treated various chemicals during the procine early embryo development to increase the mutation of target site by NHEJ(non-homologous end joining). Firstly, we confirmed the chemical toxicity after parthenogenetic activation and then check embryo puality using by counting of total cell number and TUNEL Assay in blastocyst satge. To check any improvement on mutation rate by NHEJ pathway. AZT(3′-Azido-3′-deoxythymidine, antiretroviral drug – 0.1 μM) was treated after injection of cas9 and sgRNA target to OCT4 exon 5 during the zygote stage, followed by PCR sequencing. As a result, AZT treated group shows a significantly increased in knock-out efficiency as a consequence of NHEJ. Nocodazole(anti-neoplastic agent – 200ng/ml), RO-3306 (specific inhibitor of CDK1 - 10 μM) and NU-7026(PKC signalling inhibitor - 50 μM) was treated after injection of cas9 and sgRNA with eGFP vector during the zygote stage(hpa8~hpa20) and checked a efficiency of knock-in by PCR sequencing. Interestingly, nocodazole treatment groups increased of insertion of eGFP sequence in blastocyst stage compared with non-treat group(control : 8.33%, nocodazole treatment : 16.67%). However, RO-3306 and NU-7026 made a no impact. In summary, CRISPR/CAS9 system with treatment of chemicals during porcine embryogenesis can be improving of site-specific mutation and enhancement of CRISPR genome editing.