With the change of the rules in the breaststroke style, the swimmer should be as streamlined as possible during the flat body position in the water. The current research on swimming has been improved with three-dimensional film data analysis procedure.
　On this standpoints, present study was designed to investigate the breaststroke timming of the movement and breathing for the four swimming phases syncronized by two VTR analysis data from side view in the water and front view above the water.
　The subjects of this study were japanese Olympic swimmer in Seoul during 1988, four trained and four untrained swimmers. They were sprinted 25~50 m breaststroke with their maximum effort. Swimming form devided four phases were taken by a high speed video camera (NAC HSV 400) operating at 200 fps and analyzed by a personal computer.
　The results obtained were summerized as follows ;
1) The increased swimming velocity (SV) of top swimmer was accounted for by increased stroke length (SL) and decreased stroke rate (SR) than those of trained and untrained swimmers.
2) There were significant coefficient correlations between swimming velocity (SV) and the breathing time required during arm stroke recovery phase (r= -.948, P< .001).
3) In conclusion, the swimmer should be as streamlined as possible after immediate breathing during arm stroke recovery. It was suggested that the streamlined flat body position was decrease the frontal and head on resistance, and increase the propulsive force (Lift) by using proper hands pitch and arms position.

DESCENTE SPORTS SCIENCE Vol.12/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE