A relatively perfect coefficient expression similar to a Hessian matrix in Taylor expanded formula of vector function of Hopf bifurcation f: R, which enhance visual recognition to operator coefficient of Taylor formula of vector function, here vector function f(x1,x2,...,xn,ρ ) =(f1(x1,x2,...,xn,ρ),f2(x1,x2,...,xn,ρ ),...,fn( x1,x2,...,xn, ρ))T.