The hairy root cultures of Centella asiatica were established by infection leaf explants with Agrobacterium rhizogenes A4, 15834 in 1/2 Murashing and skoog liquid medium supplemented with 50 $mu$M acetosyringone. The induced hairy roots were subjected to paper electrophoresis for the detection of opine and opine-positive clones which were considered to have been transformed. Five hairy root clones were selected according to the different bacterial strains used, growth rate and pattern. Among media tested, MS basal medium substituted phosphate concentration by 2.5mM K2HPO4 showed the highest growth rate in the dark condition.