Abstract: In Simao Region,coffee trees are attacked by Acalolepta cervinus (Hope) and Xylotrechus quadripes Chevr.,The eclosion peak of A.cervinus ranges from 18 to 30 of April,while the adults of X.quadripes chiefly emerge from October to December.The number ratio of mixed population varies with time.A.cervinus is dominant in it.The frequency of 1 borer in a tree is found to be the highest according to the frequency ditribution of the borer number in one tree.The distribution of the tree diameter where the borer tunnelled follows normal distributing,and the distributing center is 3.561 cm.The average tree height where the borer drilled is 37.072 cm,but the distribution of the drilled holes skews toward the left part of that point.These results are valuable to understanding the borers attacking mechanism and formulating the control schedule of these pests.