Objective To research the pathogen characteristics and influencing factors for peritonsillar peripheral space infections in acute tonsillitis patients, so as to take measure to reduce the peritonsillar peripheral space infections. Methods 898 acute tonsillitis patients who received treatment were chosen as study subjects.Bacteria analyzer was adopted to identify pathogens.Chi-square test was used to analyze the univariate factor, and logistic regression analysis was conducted to different factors. Results 228 patients were involved the complications of peritonsillar peripheral space infections(cellulitis in 52 cases or abscesses in 176 cases), and the infection rate was 25.4%.Bacterial cultivation performed in 177 patients and positive results were detected in 107.The top three infections bacteria were Staphylococcus aureus(21.5%), Streptococcus viridians(19.6%) and Klebsiella pneumoniae(15.9%). Univariate factor analysis found that the history diabetes and peritonsillar peripheral space infections, age, acute phase of smoking and drinking, fatigue, nutritional status, class of antibiotic use, tonsillitis type, educational level and the long first diagnosis time were risk factors for peritonsillar peripheral space infections, and the differences were significant (χ2=39.851, 8.818, 89.041, 87.266, 30.417, 21.499, 13.472, 64.548, 12.223, 62.871, 70.749, all P<0.05). Logistic regression analysis found that acute phase of smoking and drinking, age, fatigue, tonsillitis type and the long first diagnosis time were independent risk factors for peritonsillar peripheral space infections patients with acute tonsillitis (OR=2.873, 5.311, 5.876, 0.290, 2.244, 2.369, all P<0.05). Nutritional status and educational level had beneficial effect to peritonsillar infections event (OR=0.290, 0.461, all P<0.05). Conclusion Acute tonsillitis is easy to cause peritonsillar peripheral space infection, it should be paid much attention and strengthened prevention.The pathogens causing peritonsillar peripheral space infections in acute tonsillitis is still mainly Staphylococcus aureus.After the analysis of related factors, the certain measures should be taken to reduce the complications rate of peritonsillar peripheral space infections in acute tonsillitis. Key words: Peritonsillar; Infections; Etiology; Influencing factors