As from the first outbreak of COVID-19 the clinical feature of COVID-19 had been changing progressively. Various data had been reported viral intra and inter-host evolution favoring the mild COVID-19 strains are being accumulating, for better understanding the evolution of COVID-19. So it is essential to investigate the genetic and phenotypic features of this virus. COVID-19 consist various variant so larger clades had been produced and various distinct nomenclature had been proposed. In December 2020 Global Initiative on Sharing All Influenza Data (GISAID) named Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as hCoV-19 and next strain identified five clades and after that investigators identified 5 lineages (A, B, B.1, B.1.1, B.1.777). The new variant of COVID-19 identified SARS-Cov-2 VUI 202012/01 had been known of lineage B.1.777. COVID-19 associated new variant SARS-CoV-2 VUI (Variant Under Investigation) 202012/01 contains a series of mutation had been described in United Kingdom (UK) and had been found to be highly prevalent in Southeast England and London. All of this mutation is found to be more frequently transmissible than various other strains of COVID-19 Scientist are currently working on vaccine which will protect people against this virus. Currently there is not any evidence about this variant causing more serious illness or higher risk of mortality.