Abstract: The energetics of the atmosphere during the December 1980 to February 1981 when a weak stratospheric warming occured was investigated by energetic epuation in the domain of wave number.A rapid and large increase of kinetic energy for wave number 2 had a start contribution. The maintenance of warming was contributed by the kinetic energy of wave number 1.For the increase of kinetic energy of wave numbers 1 and 2, the greatest contribution term was BWZ(n), the next was L1(n),the term-M1(n) had a large contribution in a short time.