Abstract: The effects of precursors,such as coenzyme Q₀,p-hydroxybenzoic acid,solanesol,L-tyrosine,L-phenylalanine and methionine,on the dry weight of suspension cell,Q₁₀ production and intracellular Q₁₀ content in tobacco NC89 were studied with cell culture method.The results showed that:the addition of precursors could increase cell's dry weight and intracellular Q₁₀ content to a certain extent,especially p-hydroxybenzoic acid and methionine had significant effects on cell's dry weight.The coactions of either p-hydroxybenzoic acid or L-phenylalanine,together with methionine extremely significantly affected Q₁₀ content.The production of Q₁₀ changed along with cell's dry weight and intracellular Q₁₀ content.Therefore,it was allowed to apply selected precursors of proper concentration stepwisely at different cell culture phases.