The purpose of this study was to examine psychometric properties of the Dyadic Parent-Child Interaction Coding Systems (DPICS) for the use with a sample of Korean young children(3∼7 years). Subjects were 24 families with oppositional children and 30 families with normal children. Mother-child dyads were invited to the laboratory and their interactions during child-led and parent-led plays were observed. Inter-observer reliability as measured by the percentage of agreement in their observations, test-retest reliability with a one-week interval, correlations between scores of the DPICS and scores of the Eyberg Child Behavior Inventory (ECBI) were calculated and DPICS scores from families of oppositional children and families of normal children were compared. Results showed .79～.94 inter-observer reliability, .39～.54 test-retest reliability, and an evidence of concurrent validity of the DPICS. Moreover, results suggest an evidence of discriminative validity demonstrating that mothers of oppositional children displayed lower frequency of positive interactions (p<.01) and higher frequency of negative or directive interactions (p<.001) than mothers of normal children. DPICS may be useful to monitor treatment efficacy of parent-training interventions for children with externalizing disorders. Other clinical implications of the findings and limitations of the study were discussed.