This study attempted to investigate the structure of 17 body actions, consisting of 77 sub-body actions, to determine the fundamental body actions in dance from the viewpoint of kinetic force in weight qualities proposed by Rudolf Laban.On the assumption that kinetic force relates to the speed of dence movement(body action), the absolute value of the mean speed was measured at 23 body points in 231 action samples consisting of 77 sub-body actions, which were performed with three different strengths of movement, through a Frame-DIAS 2-dimensional movement analysis system.After the structure of sub-body actions had been examined by applying factor analysis to the each of 17 body actions, the fundamental body actions were investigated through factor analysis applied separately to the 77 sub-body actions, 31 subbody actions(single), and 46 sub-body actions(combination).Finally multi-step factor analysis was applied to the correlation matrices whose elements were loaded significantly on each of the factors extracted from factor analysis applied to the 77 sub-body actions.The following inferences were made.1)These factors were named jumping and turning factor, falling and recovering factor, stepping factor, and locomotion factor, which were determined comprehensively from separate application of factor analysis to the 77 sub-body actions, 31 sub-body actions(single), and 46 sub-body actions(combination).2)The first, second, third, fourth, and fifth factors extracted from the 77 sub-body actions were furthemore classified into 8 factors;jumping and turning factor, turning with jumping or stepping factor, locomotion with jumping or turning factor, falling and recovering factor, locomotion with stepping or gesture factor, stepping factor(2), stepping factor(1), and locomotion factor, through multistep factor analysis.3)With reference to the kinetic force of body actions in dance, the following four domains of body action were determined as the fundamental body action in dance:jumping and turning, stepping, falling and recovering, and locomotion.