Abstract The shape of old crotch scars on tree trunks was investigated，and the effects of hole shape on the mechanical strength of the plates with a hole were analyzed with a finite element software ANSYS．The Mises stress is used to evaluate the strength of the plates with a hole．Resuits dem onstrate that the elliptical hole，which elliptical parameter is larger than 2，has the best mechanical performance，as the plate is under uniform load in one direction．Also，results show that the circular hole has the best performance is the best one，as the ratio of the uniform loads in two directions is 0.5— 2.0．
