Abstract: Egg scar patterns of 11 species of the conifer sawfly family Diprionidae inYunnan are described and illustrated for the first time. These species belong to 4 genera:Diprion, Nesodiprion, Neodiprion and Gilpinia, The egg scar patterns can be used asdiagnostic characters for the species,b ut can not be used for the distinguishment ofgenera. A key based on egg scar patterns is given for the species.The species whose femaleadults oviposit 1 or 2 eggs on one needle,the larvae are non-gregarious and usualIy causeno destruction,In contrary,the species whose female adults lay many eggs on oneneedle,th e larvae are gregarious and often cause outbreaks in the forest.