Abstract:Immature endosperms (female gametophyte) of Pinus bungeana Zucc. and P. tabulaeformis Carr. were used as explants for establishing tissue cultures. Calli induction and differentiation were studied on a modified MS medium containing 3 % sucrose and various concentrations of auxins and cytokinins. Callus tissues of P. bungeana and P. tabulaeforms could be induced on media supplemented with 1--6 mg/L naphthoxyacetic acid and 0.5 mg/L 6-BAP. The highest induction frequency of calli was 250%. Histocytological observation revealed that the callus cell was haploidy with, N= 12. Differentiation of green buds occurred on the medium supplemented with 0. 1 mg/L ABA, whereas no plantlet was developed, however.