Streptococcosis is the general term for a variety of diseases caused by members of the genus Streptocoocus, lactococcus Enterococcus, Vagococcus. Streptococcus iniae, Streptococcus agalactiae, Streptococcus dysgalactiae and Lactococcus garvieae have great concern that can seriously cause significant losses in the global aquaculture development especially Nile tilapia production. The most common clinical signs of disease are meningoencephalitis, skin lesion, abdominal distension, exophthalmia, and corneal opacity. The disease outbreaks are usually during the summer season and pathogen transmitted mainly by horizontal route. To reduce economic losses and combat disease outbreaks, several preventive and control measures have been developed. Vaccination via oral method is a very promising measure for mass protection of fish against disease compared to other application routes. As well as Strept. iniae chitosan nanoparticle vaccines showed significant improvement in fish immunity and high survivability against the disease.