Abstract: Stem-tips of pineapple (Ananas comosus (L.) Merr.) were cultured on a modified MS medium supplemented with various concentrations (1.0, 2.0, 3.0, 4.0, 5.0, 6.0 mg.L-1) of adenine (Ad). There were no significant effects on shoot culture and bud proliferation culture as compared with the contrast (Ad-free MS medium). However, bud growth rate on the stage of elongation culture was significantly higher than the control, under the Ad concentrations more than 1.0 mg.L-1 mg in the medium.The results also showed that the concentrations (3.0～5.0 mg.L-1) of Ad are the best for bud elongation. In these conditions, the period of elongation culture can be reduced 30 days at least.