Gene for phosphoenolpyruvate carboxylase (PEPCase) was incorporated in antisense orientation into genome of japonica rice variety Xiushui 11 through Agrobacterium tumefaciens-mediated transformation of mature seeds-derived embryogenic calli, and a total of 95 transgenic plants were regenerated, which were confirmed by histochemical detection of GUS activity (Fig.2), PCR assay (Fig.3) and Southern hybridization analysis (Fig.4). The transgene was inherited by the T1 progeny and Mendelian 3:1 segregation ratio was observed in most transgenic lines. It was found that the fat content of hulled grains of T2 transgenic lines was 0.37 +/- 0.12 per cent higher than that of the control, most of which were statistically very significant (Table 2).