Chlorovirus is one of the most interesting viruses infect the algae.This virus infect the unicellular chlorella lie green alga strain NC64A. Analysis of the genes among the chloroviruses genome revealed very interesting rearrangement in genes along the genome.This work carried out to study the characterization of chitinase and chitin synthase genes involved in the interaction between chlorovirus and its host cell. Analysis of the genome of chlorovirus and chlorella cells illustrate helpful information in the relationship during the virus infection. Comparison of the genes arrangement between different chloroviruses has revealed gene replacements on the virus genome which help to know the essential genes for virus host interaction.