Objective:To analyze risk factors of central venous catheter which is related to infection and to present prevention strategies in critical patients. Methods: This clinical research was conducted on 363 cases of critical patients with central venous catheters via subclavian and jugular veins, to analyze risk factors of central venous catheter related blood stream infection and to present rational prevention strategies. Results: A total of 65 cases of CABI occurred after cental venous catheterization, with a 1 000-day infection rate 18.5‰, and case infection rate of 17.9%. CABI mostly occurred in senile patients (especially over 70 s),who are male, catheter time over 2weeks, or with high APACHE II values, however, nutrition status, MODS and diabetes did not play a critical role on CABI occurrence. Besides, multiple factor analysis reviewing male and catheter time over 2 weeks were closely related with CABI occurrence. Pathogen distribution revealed dominance of gram positive coccus (53.6%), which in proper sequence were staphylococcus epidermidis, aureus, haemolyticus and enterococcus faecium; second predominant pathogens were gram negative bacillus(37.5%), which in proper sequence were acinetobacter baumannii, pseudomonas aeruginosa and klebsiella pneumoniae; Fungi contributed 7.1% of CABI pathogen, which was mainly candida krusei. Conclusion: In this research, senile critical patients had higher occurrence of CABI, and the main strain of pathogen was gram positive coccus. Risk analysis pointed out that thoese paitents with old age, especially over 70 s, male gender, and with catheter time over 2 weeks and higher APACHE Ⅱ scores suffer high risk of CABI. Meantime, this research did not present remarkable connection between CABI and nutrition status, MODS, and diabetes.