Three aquatic plants, Glossostigma elatinoides (Benth.) Hook.f., Limnophila sp. (unidentified), and Microcarpaea minima (K.D. Koenig ex Retz.) Merrill. were examined to clarify the optimal culture medium and cultural conditions for their micropropagation. Murashige and Skoog (MS) medium strength (1/1, 1/2, 1/4 and 1/8), sucrose concentration (0, 10, 20, 30, and 40 g•L-1), initial pH of medium (4.5, 5.0, 5.5, 6.0, and 6.5), and the kind and concentration of gelling agent (6, 7, 8, 9, 10 g•L-1 for agar and 3 g•L-1 for gellan gum) were examined. The optimal medium conditions for all of the examined plants was ½ MS, 20 g•L-1 sucrose, and 3 g•L-1 gellan gum. The optimal medium pH was 5.0 for G. elatinoides and 6.0 for M. minima and Limnophila. Water supplement during culture was effective on the growth and acclimatization of multiplied plants. The optimal timing of supplement was after 20 days for G. elatinoides and 30 days for M. minima and Limnophila from the explant inoculation.