Abstract: This paper reports the morphological description of the different stages of the mango stone weevil (Sternochetus olivieri Faust) and the comparision in morphology with species that are closely related to S. mangiferae Fabricius. The observations on the life history and biological habits in a mango grove in southern Yunnan were made from 1985 to 1987. Some of the biological habits which have not yet been reported in previous literatures are reported. An analysis of the effects of the local weather factors on the pest population dynamics is also made. The role of the predators and a fungus pathogen of the weevil is introduced, and the vulnerability of the host varieties to the weevil attack is stated. The historical changes of generic names of S. olivieri and the distribution of the four Sternochetus species of the mango weevil are included as well.