Abstract: Fruits and immature embryos sampled from hybrids between Pistacia vera and Pistacia chinensis were used to study the fruit growth pattern and the effects of different embryo developmental stages，the varieties of medium and concentrations of 6-BA in culture medium on hybrid plants regeneration. The results showed that：（1）The hybrid fruit growth had a single-peak curve pattern in terms of the changing of fruit length and diameter during fruit development，and had a double“S”curve in terms of the changing of fresh weight.（2）The development of hybrid embryo began from 80 days after pollination，and the critical period for the hybrid embryo abortion was from the 80 to 100 days.（3）The hybridimmature embryos collected at 80 days after pollinationdid not germinated while that collected at 100 days and 120 days germinated at rates of 37.04% and 83.33% respectively.（4）The suitable multiplication medium for immature embryo seedlings was DKW + 2.0 mg · L^-1 6-BA + 0.05 mg · L^-1 IBA + 0.3 g · L^-1 LH + 1.5 g · L^-1 PVP，with which the multiplication coefficient of 3.47 and the seedling height of 3.32 cm were obtained.（5）The suitable rooting medium was 1/2 WPM + 2.0 mg · L^-1 IBA + 0.05 mg · L^-1 NAA with a rooting rate of 80%．

Key words: pistachio, hybrid, embryo culture