Abstract: OBJECTIVE To established the andrographolide nanosuspensions (ADG-NS) with improved its dissolution and membrane permeability. METHODS ADG-NS were prepared by wet media milling technique. The quality of the nanosuspensions was characterized including the particle size and distribution， Zeta potential， particle morphology and crystal physical state. In vitro dissolution test and Caco-2 permeability test were used to preliminarily evaluate the ADG-NS. RESULTS The particle size， polydispersity index (PDI) and Zeta potential of ADG-NS were (215.6 ± 3.3) nm， 0.165 ± 0.020 and (-36.9 ± 2.8) mV， respectively. SEM analysis showed that there was no adhesion and aggregation between particles， the particles were rod or block， and the size distribution was uniform. DSC and XRPD results showed that the nanoparticles were present in the amorphous form. The dissolution rate of ADG-NS were significantly enhanced in different pH buffer solutions compared to ADG and commercial dripping pills. Caco-2 permeability test revealed that ADG-NS showed a significant increase in the membrane permeability (P_app) compared to the group of ADG (P<0.01). CONCLUSION The ADG-NS prepared by wet media milling technique can improve the in vitro dissolution rate and membrane permeability of andrographolide (ADG).