The effects of paclobutrazol on growth, sex expression and resistance to chilling in jury of cucumber seedlings and fruit yields were examined in a series of pots and field. Stem elongation and leaf area growth were inhibited. But stem diameter and root development were stimulated, leaf chlorophyll was increased and chilling susceptility was decreased at all levels of paclgbutrazol tested. These changes caused by paclobutrazol in cucumber seedling were reversed effectively by GA3. Paclobutrazol decreased node location of lst female and increased femaleness also. The total fruit yield was increased 9.3% to 13.6% at 50 ppm and 100ppm, respectively.