Abstract: The somatic chromosome number and detailed chromosome morphology of six Ranunculusspecies in Sichuan were studied. The results show that their chromosome numbers are 2n=16 forR.tanguticus, 2n=32 forR.nephelogenes, 2n=16 forR.ficariifolius, 2n=32 for R.sceleratus, 2n=14 forR.japonicus, and 2n=16 forR.silerifolius. From these chromosomal data, the genetical relationships of four sections inRanunculuswere discussed. The conclusion is that sect.Ranunculus among the four sections shows an advanced level in evolution.