This paper investigates the Hopf bifurcation of a delay competition diffusi
on system. Our purpose is to give more detail information about the Hopf bi
furcation solutions of this system. We derive the basis of the eigenfunctio
n subspace then convert the existence of the periodic bifurcation solution
to the study of the existence of the implicit function and obtain the asymp
totic expression of periodic solutions. Moreover we determine the bifurcati
on direction which is useful for analyzing the properties of periodic solut
ions.