In this paper we discuss the changes in the number of plants developed per embryogenic mass, the percentage of embryogenic masses that developed plants, the percentage of plant regeneration, and the index of vigor of regenerated plants for embryogenic masses that were induced from daily samples of a cell suspension culture of rice (Oryza sativa L. cv. Taipei 309). The results indicate that embryogenic masses that matured first and were induced from freshly subcultured cell suspension culture had the highest values for the four parameters. An index of vigor of the regenerated plants was defined.