Abstract: The experiment of using different concentration, periods and methods to apply Mo⁶⁺ to tobacco plants was conducted.The results showed that experiment could coordinate the physiology metabolism, meet the nutrition and improve the botany properties, which would result in high yield and quality. The best treatment was the leaves spraying of 0.5g/kg (NH₄)₆Mo₆O₂₄·H₂O at the seedling-renewknee-high stage one time. The better treatment was the leaves spraying of 1.5g/kg (NH₄) ₆Mo₆O₂₄·H₂O at the Knee-high stage two times and applying fertilizer of 2.5g/kg (NH₄)₆Mo₇O₂₄·H₂O to the root area at the rapid growth and enlongation stage one time. The tobacco plants applied Mo⁶⁺ got a better quality than those not applied Mo⁶⁺.