Abstract: M orpho logy of immature stages and bio log ical characterist ics o f tw o papilionid butterflies, Pap ilio memnonL. and P. helenus L. w ere observed. The adu lts o f both the species v isited flow ers such as those ofLantana camaraL inn. ( V erbenaceae ), C lerod endrum bungei Steud. ( Verbenaceae ) and Sambucus sp. ( C aprifo liaceae ), andthe non gregarious larvae had five instars. The experimental populat ions o f bo th the two spec ies are mu lt ivoltine,and had 3 and 5 generations a year forP. m emnon L. and P. helenus L., respectively. WhileP. m emnon L. usedC itrus spp. ( Ru taceae ) as hostplants atM.t Eme,i S ichuan Prov ince, P. helenus L. used mainly those in generaC itrus and Zanthoxy lum of the same fam ily in south Yunnan Province. Some exce llent hostplants used in the large scale breedings o f the tw o butterfly spec ies are also recommended.