Abstract: Cultured 2 weeks in vitro on medium (SH+1-2mg/1 BA+3% sucrose) for differentiation, mature embryos of P.koraiensis were transferred to the medium without hormone (SH+3% sucrose), Adventitious buds pro-duced on epicotyls and hypocotyls continuously, The organogenesis process of adventitious buds was observed with paraffin section method. The results showed that the adventitious:bud arose from cortical cell of hypocotyls, some of them originated from.both cortical cells and epidermis cells.The whole process of adventitious buds development in culture could be.divided into four stages as follows.(1)starting of cells differentiation;(2)bud primordium;(3)shoot apex with needle primordia;(4)adventitious buds.

Key words: Pinus koraiensis, tissue culture, adventitious buds, morphological formation