Abstract: Anthers of two indica rice varieties "Hua03","E Zao No. 6" and one japonica rice variety "105" containing Pollens developed at mid-to late-uniuncleate stage were treated with different concentration of EMS at 27± 1℃ for 3 hours before inoculating on GM medium. Effects of EMS on the frequency of callus induction and plantlet regeneration were observed, and the respiratory intensity of anther was determined on the third and sixth day during the culture. The experimental results showed that lower dose of EMS could significantly increase the anther callus formation. As the dose of EMS increased, the frequency of callus induction decreased rapidly. The effect of EMS on respiratory intensity was in accordance with the frequency of callus formation.