Abstract: Transcription factors ABSCISIC ACID-INSITIVE3(ABI3),LEAFY COTYLEDON(LEC2)and FUSCA3(FUS3)play important roles during seed development.The RNA extracted from peanut root,stem,leaf and developing cotyledon were hybridized by probe from the conserved B3 domain of Arabidopsis ABI3 protein.The micro sections of root,stem,leaf and developing cotyledon(including embryo) of peanut were also hybridized in situ with the same probe.The positive results of hybridization signals only in peanut cotyledon reveal that the homologous gene of ABI3,FUS3 and LEC2 may exist in peanut and they only distributed in the cotyledon and embryo of peanut.