[Objective] This study aimed to investigate the variation rule of total RNA concentration during formation of microtubers of Pinellia ternata induced by sucrose. [Method] Plantlets of P. ternata were used as experimental materials. Total RNA concentration was determined with spectrophotometer, and the variation of total RNA was analyzed before and after formation of P. ternata microtubers treated with different concentrations of sucrose using DDRT-PCR technology. [Result] Total RNA concentration of P. ternata treated with different concentrations of sucrose varied greatly, which showed an upward trend in the first 15 d, declined from 15th d to 25th d, and slightly raised from 25th d to 30th d. Microtubers formed under various sucrose treatments showed an increase in RNA concentration after induction, and it was assumed that the treatment of high concentrations of sucrose might have activated the expression of development-related genes in P. ternata microtubers. [Conclusion] This study provides the basis for revealing the related gene expression information and molecular mechanism during formation of P. ternata microtubers induced by sucrose. [Objective] This study aimed to investigate the variation rule of total RNA concentration during formation of microtubers of Pinellia ternata induced by sucrose. [Method] Plantlets of P. ternata were used as experimental materials. Total RNA concentration was determined with spectrophotometer, and the variation of total RNA was analyzed before and after formation of P. ternata microtubers treated with different concentrations of sucrose using DDRT-PCR technology. [Result] Total RNA concentration of P. ternata treated with different concentrations of sucrose varied greatly, which showed an upward trend in the first 15 days, declined from 15th d to 25th d, and slightly raised from 25th d to 30th days. Microtubers formed under various sucrose treatments showed an increase in RNA concentration after induction, and it was assumed that the treatment of high temperature of sucrose might have activated the expression of development-related genes in P. ternata microtubers. [Conclusion] This study provides the basis for revealing the related gene expression information and molecular mechanism of formation of P. ternata microtubers induced by sucrose.