As the dry weight to fresh weight ratio of Panax notoginseng cells is related to the medium sugar concentration, the osmotic pressure can be increased by adding glucose to change cells’ water content. When the apparent viscosity was decreased from 80.1 to 10.2 cp the surface O-2 transfer coefficient (K(L)a) increased from 4.80 to 5.68 h(-1) by adding 1.23 g glucose to 50 ml culture medium after 24 h.