Purpose: This study was conducted to develop and test a measurement of the suicidal protection(MSP) for high school students in Korea. Methods: Thirty-four preliminary items were initially developed based on literature review and focus group interviews. Those items were evaluated by experts for content validity with 31 items yielded. For testing validity and reliability of the measurement, data were collected from 330 high school students in Korea. Results: The item analysis selected 26 items. One item was deleted additionally through the primary exploratory factor analysis. The final exploratory factor analysis yielded 26 items in six factors such as fear of suicide, self-esteem, emotion regulation, support from others, support from family, and school life, explaining 66.6% of the total variance of the suicidal protection for high school students in Korea. Convergent validity and discriminant validity were supported by construct reliability, average variance extracted estimate, and standardized regression weight. MSP scores were positively associated with economic status, academic record and suicidal ideation. Also, criterion validity was supported through a significant correlation with the Reason for Living Inventory for Adolescent. The Cronbach's α reliability coefficient was .93 for the overall measurement and .72~.86 for the six factors. Conclusion: The results show that MSP may be valid and reliable for assessing suicidal protection of high school students.