Purpose: The purpose of this study was to verify the relationships among social support, resilience and post traumatic stress disorder (PTSD), andespecially to identify factors influencing PTSD in police crime scene investigators. Methods: A cross-sectional design was used, with a conveniencesample of 226 police crime scene investigators from 7 Metropolitan Police Agencies. Data were collected through self-report questionnairesduring July and August, 2015. Data were analyzed using t-test, c 2-test, Fisher’s exact test, and binary logistic regression analysis with SPSS/WIN 21.0 program. Results: The mean score for PTSD in police crime scene investigators was 13.69䔳 .11 points. Of the crime scene investigators181 (80.1%) were in the low-risk group and 45 (19.9%) in high-risk group. Social support (t=5.68, pqqqlt;.001) and resilience (t=5.47, pqqqlt;.001) werehigher in the low-risk group compared to the high-risk group. Logistic regression analysis showed that resilience (OR=4.74, 95% CI: 1.57∼14.35),and social support (OR=2.13, 95% CI: 1.23∼3.69) are effect factors for PTSD low group. Conclusion: For effective improvement of PTSD in policecrime scene investigators, intervention programs including social support and strategies to increase should be established.