Abstract: In the study of dissimilar steel welded joints of medium and high carbon pearlitic steel welded by Cr30Nil0 type covered electrodes, the authors find that there is a special band of austenite near the fusion line of welded joint. In that band, termed as the "Austenite-Rich Band",there are uncontmuous structures of martensite and ferrite. The funetion and formation mechanism of the "Austenite-Rich eand" and the effet on the ek-resisting ability and toughness of the joints are explored and analysed.