With the breakthrough research progress of gravitational wave detection and telescope observation of black hole event horizon, the quasi-normal mode of black hole has caused a new round of research upsurge. The quasi-normal mode of black hole is described as the eigenfunction of time independent Schrodinger equation with complex frequency by many literatures. Such description leads readers to a misunderstanding that the concept of quasi-normal mode comes from the Schrodinger equation, or quantum mechanics. The current paper will analyze this issue and point out that there is no quantum mechanical analogous to the quasi-normal mode of black hole. We clarify the relevant physical concepts and point out that quasi-normal modes are the physical behavior of wave equations admitting dissipation characteristics.