Purpose: The purpose of this study was to develop a Korean problem solving process inventory (K-PSPI) for adults. Method: A conceptual framework for the adult problem solving process, and 40 preliminary questions were developed based on references and expert consultations. After a pilot test, preliminary questions were further refined. The final inventory of 30 items was tested with 1,500 adults. The validity and reliability of the K-PSPI were tested by factor analysis using the SPSS Windows 12.0 program. Results: Through factor analysis on the final 30 questions, 5 factors were identified and cumulative variant of the factors was 52.15%. For the test of reliability of the 30 questions on the problem-solving process, The Cronbach alpha was .93. Conclusion: This study showed that the K-PSPI is a systematic method with verifies reliability and validity. It is not only adequate for the actual circumstance and culture of Korean adults, but is also a useful instrument to test post-action problem solving ability.