Abstract: Based on the normally o ment for harmonic oscillator is deduced c harmonic oscillator＇s eigenstate, and the concise rdered form of operator （fX＋gp）^k ompactly by virtue of the relation k be result is also discussed. It is clear , the general formula of its matrix ele- tween un-normalized coherent state and that this adopted method is very simply

Key words: harmonic oscillator, Hermite polynomial, normally ordered product, matrix element