Conglomerate in Baiyan formation distributes in limestone outcropped area in western Shandong which occurring in karstens, karst valleys and karst caves. Chert with good abrasion is the major content in conglomerate, and diamonds are contained in it generally. Its facies, structure and geneses are complicated. Through analysis on characteristics, forming process, time and origin of diamond, it is regarded that there are unfound primary diamonds in Baiyan Area in western Shandong.