The aim of this study was to develop and validate the State-Posttraumatic Growth Scale based on Mindfulness(MS-PTGS) to measure the state of growth shown in the process of Posttraumatic Growth convergently. As most studies of Posttraumatic Growth have measured various results of it obtained after coping with trauma, there is no scale for measuring the process of it. The initial MS-PTGS consisted of 58 items and 2 factors, which were based on ‘if the response of PTSD symptoms then Awareness and Acceptance’, which is the pattern of measurement of the construct of MS-PTGS developed by literature reviews. By considering the limitation of items including if-clause, Scale type 1 and Scale type 2 were developed. After items, which included overlapping meanings, were removed and their contents were examined by experts, 36 items of each Scale were selected. Through pilot study, 17 items of Scale type 1 and 16 items of Scale type 2 were selected. Finally, Scale type 2, which was more suitable for the construct, was selected as MS-PTGS examining item analysis, explanatory factor analysis, reliability analysis, and convergent validity in the main study. Logical validity was examined and verified. These results suggest that MS-PTGS is a reliable and valid tool for measuring the state of growth shown in the process of Posttraumatic Growth convergently. The significances of this study are the suggestion of possibility for a deep research regarding PTG and the usefulness of a plan for therapeutic strategy regarding those who have experienced trauma.