The current study investigates which factors affect police officer's job satisfaction. Based on previous research, 24 independent variables are constructed and categorized into 6 elements. Frist, the sociodemographic characteristic element consists of 11 factors: gender, age, marital status, employment period, department, position, entering channel, education level, working unit, wage, and working location. Second, for the job related element, two factors, stress and burden of duty are examined. Third, the human relationship element includes two factors, relations with boss and colleague and perception of leadership. Fourth, the working environment element consists of 4 factors, promotion, punishment, welfare service, and wage. Fifth, regarding the organizational culture element, 4 factors , rationality culture, hierarchy culture, development culture and group culture are examined. Sixth, the external environment element includes the public's trust and respect toward police. A self-administered survey was conducted in the Police Training Institute where police officers from 16 local police agencies receive regular training. Six hundred questionnaires were administered and with overall 84.7% respondent rate, a total 508 questionnaires were analyzed through the SPSS(Statiscal Package for the Social Science) WIN 20.0. Research findings are followings: First, in regards to the sociodemographic factors, age, marital status, employment period, department, position, entering channel, education level, working unit, and working location are statistically significant factors affecting job satisfaction. Second, for the job related factors, police officers with more job related stress and burden of job duty are more likely to demonstrate low levels of job satisfaction. Third, regarding the human relationship element, relations with boss and colleague and perception of leadership are significant factors affecting job satisfaction. That is, a police officer with a good relationship with boss and colleague and who demonstrate a higher respect toward the boss's leadership is more likely to be satisfied with his/her job. Forth, among the working environment elements, promotion, punishment, welfare service, and wage are significant factors. Fifth, regarding the organizational culture element, rationality culture, hierarchy culture, and group culture significantly affect the police's job satisfaction. Sixth, among the external environment element, a police officer who has a strong belief that the public trusts and respects the police officers is more likely to be satisfied with his/her job. Based on research findings, three policy implications are presented. First, working environment for street police officers needs to be improved. Extra pay, expanded working space and benefits of promotion should be considered. Second, appropriate measures should be taken to address police officers' job related stress. While taking health medical examination, a police officer needs to receive mental health checkup in addition to physical health checkup. Furthermore, counseling program for police officers should be implemented in all the police stations. Third, to improve the morale of police officers, expanding reward for hardworking and enhancing welfare service are needed. Forth, to improve relationships among police officers, specific programs should be developed. A friendly atmosphere is expected to relieve police officers' stress level as well as to improve the hierarchial subculture of police organization. Fifth, more factors affecting police officer's job satisfaction need to be investigated along with the cooperation of private sectors.