The present disclosure relates to a method, a medium, a program product, and a modem for setting modulation modes. The method includes detecting by a modem whether a modulation mode of the modem is inverted, the modem being capable of operating in a plurality of modulation modes, and each modulation mode having a different modulation order; and in response to the determination that the number of times of inversion of the modulation mode within a first predetermined time has reached a threshold, setting by the modem the modulation mode of the modem to a modulation mode other than a modulation mode with the highest modulation order in all modulation modes included in the inversion process and maintaining the set modulation mode for a second predetermined time. By the above method, the modulation mode is prevented from repeatedly inverting, thereby maintaining the downstream data throughput at a high level.