Peritonsillar abscess is the suppurative inflammation of the peritonsillar space which manifests at the early stage as phlegmon of peritonsillar tissue, and then will develop into abscess. The disease generally occurs unilaterally, mostly in young people and those below 50. The disease is the secondary disease of tonsillitis at the stage of acute attack. Due to foreign body in the tonsillar fossae, especially when the tonsillar fossa is obstructed, drainage will be inadequate, causing the infection to develop deep.This will penetrate the tonsillar capsule to enter the peritonsillar space, giving rise to the disease. The disease and acute tonsillitis have the same commoly-seen pathogenic bacteria such as Staphylococcus aureus, beta hemolytic Streptococcus and a-Streptococcus viridans.