The purpose of this study was to examine the effect of a special training program termed "negative loading training". Ten female junior collage basketball players were divided into two groups. The first group (Gf : N = 5) was involved in free vertical jump with counter-movement. The second group (Gn : N = 5) was assigned to conduct negative loading training which involved each member vertical jumping while she was pulled upward by rubber rope attached to her hip belt with pulling force of 10% of her body weight. They jumped with all their might 10 times a day with 15- second rests between the jumps, 3 days a week for 8 weeks in addition to their regular basketball training. After 8 weeks of training, the following results were obtained.
　1) Height jumped has significantly increased only in Gn (P<0.05).
　2) Kicking time in Gn increased significantly compared with that in Gf (P<0.05).
　3) Kicking distance in vertical direction in Gn increased significantly compared with that in Gf (P<0.01).
　4) Mean power did not significantly change either' in Gn or Gf.
　From these results it was suggested that negative loading training was effective in increasing in vertical jumping ability. Also, it seemed that the effect was caused not by increment in mean power but increment in kicking time and kicking distance.

DESCENTE SPORTS SCIENCE Vol.17/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE