Abstract: Quantum tunneling is a very important quantum phenomenon in quantum mechanics. The question of one-dimensional barrier penetration is studied in this paper. Three different forms ofthe results, namely,differences of the energy of the particle, E〉Vo, E〈Vo and E= V0, can be unified by employing ＂effective barrier＂. Some physical phenomena about one-dimensional barrier penetration are discussed in the extreme conditions.

Key words: quantum tunneling, one-dimensional barrier, penetration coefficient