PURPOSE: The purpose of this study was to develop an instrument to measure family resilience for Korean families with a chronically ill child, and to test the validity and reliability of the instrument. METHOD: The items of instruments used based on the researchers' previous study of concept analysis of Korean family resilience. Nineteen item scales were developed with five domains. In order to test reliability and validity of the scale, data were collected from 231 families, who had a child with a chronic illness. Data was collected between August and September of 2001 in a 3rd level University Hospital in Seoul, Korea. RESULT: The results were as follows: As a result of the item analysis, 19 items were selected from the total of 37 items, excluding items with low correlation with the total scale. Five factors were evolved by factor analysis, which explained 56.4% of the total variance. The first factor 'Family strength' explained 28.5%, 2nd factor 'Family maturity' 8.7%, 3rd factor 'The ability to use of external resources' 7.0%, 4th factor 'Control' 6.6%, 5th factor 'The driving force for finance' 5.7%. The attributes in these factors were different with those identified by concept analysis of the family resilience in Korean families from the previous study. Cronbach's alphacoefficient of this scale was .8039 and Guttman spilt- half coefficient was .8184. CONCLUSION: The study support the reliability and validity of the scale. Because the main concept of family resilience was family strength, there were distinct differences in dimensions of family functioning scales.