Hyoscyamine and scopolamine are two most common tropane alkaloids found in the Solanaceae. The pEB expression vector carrying Nspmt gene was transformed to Agrobacterium rhizogenes. The growth of transgenic hairy roots were approximately to 80% of the wild type root. Transgenic hairy roots are less developed on only their branch roots than those of the wild type root. The extracts from Nspmt transgenic hairy root lines, 3 and 5 contained between 3.52 and 4.23 mg/g dry weight as hyoscyamine and did between 5.23 to 6.40 mg/g dry weight as scopolamine. These results showed that the overexpression of the pmt gene enhanced tropane alkaloids production of S. parviflora transformed roots and this improvement affected both hyoscyamine and scopolamine production.