INTRODUCTION: IN BASKETBALL, A RUNNING SINGLE LEG JUMP IS FREQUENTLY USED IN VARIOUS COMPETITIVE ACTIVITIES SUCH AS REBOUNDING, BLOCKED SHOTS AND LAY-UP SHOTS AT A HIGHER POSITION. HENCE, THE ABILITY OF THE LAYUP JUMP IS A DETERMINANT FOR ACHIEVING HIGH COMPETITIVE PERFORMANCES IN THIS SPORT.METHODOLOGY: THE PURPOSE OF THE STUDY WAS TO IDENTIFY THE CRUCIAL VARIABLES THAT CONTRIBUTE TO A SUCCESSFUL BASKETBALL LAYUP PERFORMANCE BY USING BIOMECHANICAL ANALYSIS. THIRTEEN MALE BASKETBALL PLAYERS PERFORMED 3 SINGLE LEG JUMPS. THREE-DIMENSIONAL COORDINATE OBTAINED WITH RAPTOR CAMERA INFRARED MOTION ANALYSIS SYSTEM (MAC 3D SYSTEM) AT A SAMPLING FREQUENCY OF 500-HZ AND SYNCHRONIZED TO EACH OTHER WERE USED. IN ORDER TO LOCATE SEGMENTS AND JOINTS, MARKERS WERE ATTACHED AT 9 IDENTIFIED SECTION OF THE BODY ON THE RIGHT SIDE OF EACH SUBJECT: THE HEAD OF THE 2ND DORSAL PHALANX (TOE), BASE OF THE CALCANEOUS (HEEL), LATERAL MALLEOLUS (ANKLE), LATERAL CONDYLE OF THE FEMUR (KNEE), GREATER TROCHANTER (HIP), GLENOHUMERAL JOINT (SHOULDER), CHIN-NECK INTERSECTION (HEAD), HEAD OF RADIUS (ELBOW), AND ULNAR STYLOID PROCESS (WRIST). SIMI MOTION 7.5 MOTION ANALYSIS PROGRAM WAS USED TO MAKE KINEMATIC ANALYSIS. COORDINATE DATA WERE FILTERED AND THEN KINEMATIC VARIABLES WERE CALCULATED TO DESCRIBE THE BASKETBALL RUNNING SINGLE LEG JUMPS PERFORMANCE RESULTS: THE RESULTS OF THE PRESENT STUDY REVEALED FIVE VARIABLES THAT STRONGLY CONTRIBUTED TO JUMP HEIGHT ACCORDING TO MODEL SELECTION. IN THE APPROACH PHASE, THE HORIZONTAL VELOCITY OF COM WAS A CONTRIBUTOR. THE SHOULDER JOINT ANGULAR VELOCITY WAS THE ONLY VARIABLE IDENTIFIED IN THE FLIGHT PHASE. THE REMAINING FOUR VARIABLES WERE FROM THE TAKEOFF PHASE: HIP JOINT ANGULAR VELOCITY, ANKLE JOINT ANGULAR VELOCITY AND MAXIMUM NEGATIVE VERTICAL VELOCITY OF COM DURING TAKEOFF.DISCUSSION: THE CURRENT RESULTS INDICATE THAT ANKLE JOINT ANGULAR VELOCITY DURING THE TAKEOFF PERIOD WAS SIGNIFICANT PREDICTOR THAT IS IN ACCORDANCE WITH THE RESULTS OF SUGIYAMA AND ET AL (2014) FOR JUMP HEIGHT [1]. ALSO, IT IS VERY IMPORTANT TO USE THEIR ARMS CORRECTLY AT TAKEOFF AND FLIGHT PHASE ARE CORRELATED WITH THE JUMP HEIGHT THAT WAS CONSISTENT WITH LEES AND ET AL (2004) IT WAS FOUND THAT THE ARM SWING AFFECTS THE JUMP HEIGHT [2]. THEREFORE, IT IS VERY IMPORTANT TO USE THEIR ARMS CORRECTLY, THE HIP EXTENSION SPEED, ANKLE JOINT ANGULAR VELOCITY, HORIZONTAL VELOCITY OF COM AND MAXIMUM NEGATIVE VERTICAL VELOCITY OF COM AT LAYUP JUMP THAT ARE CORRELATED WITH THE JUMP HEIGHT.