COVID-19 associated infection is caused by the virus SARS-CoV-2, the virus is single stranded positive sense binds with greater affinity to Angiotensin Converting Enzyme-2 present in human cells it is 30 kb pair long RNA genome which take over the host cell machinery, immune system of host cell with the help of accessory proteins leads widespread infection. COVID-19 contains structural protein spike, membrane, Nucleocapsid, and envelope. The epidemiology of COVID-19 is based on dynamics of RdRp, N, and E genes for diagnosis of COVID-19 and knowing the exact understanding of this infection. The protein RNA dependent polymerase (RdRp) is responsible which performs replication of virus in host cell. As there is not any homolog of RdRp is seen till now, so it can be a promising gene for COVID-19 associated diagnosis. There are mainly two techniques responsible for detection of COVID-19 associated infection one is immunological assay performed through antigen and antibody and other is molecular technique based of genome analysis real-time reverse transcriptase polymerase chain reactions (RT-PCR). Among both of them more reliable is RT-PCR which is based on diagnosis of RdRp gene, N-gene, E gene. Envelope protein is involved in assembly, budding and pathogenesis of virus also perform viroporin and interacts with host cell and CoV proteins. Nucleocapsid protein is involved in forming complexes membrane of virus and its assembly this protein is also involved in increasing the transcription efficiency of virus, recent studies had revealed that N-proteins are the multifunctional protein. This review article aim is to reveal the functioning of all the three genes (N, E and RdRp) associated SARS-CoV-2 infection.