Abstract: This paper studied the change of DNA, RNA and protein during growth of callus of Baibaili tobacco (Nicotiana tabacum Baihaili) with bad, root aud both bud and root differentiation respectively. The culture media containing MS+NAA 0.2 mg/l+KT 0.2 mg/l, MS+NAA 0.05 mg/l+KT 2 mg/l and MS+NAA 0.5 mg/l+KT 0.05 mg/l respectively induced Baibaili tobacco callus to he both bud and root, bud, and root organogensis. The peaks of DNA, RNA and protein in callus with bud differentiation and the peaks of RNA and protein in root differentiation were five days later than the peaks of DNA, RNA and protein in callus with both bud and rootThe peak of DNA in callus with root differentiation was the same as in callus with both bud and root differentiation. It seems that the influence of exogenous growth regulators inducing orientation organogensis is on RNA.There was notable different in the compositions of soluble protein of callus with bud, root and both bud and root differentiation. It also seems that 41 KD and 46 KD proteins might have important actions in orientation organogensis.