A method for adjusting a Modulation and Coding Scheme, MCS, comprising: receiving, by a user equipment, UE, a first downlink data frame sent by a base station at a first moment, and estimating a first Signal to Interference and Noise Ratio, SINR, and a first Channel Quality Indicator, CQI, according to the first downlink data frame (101, 301, 401, 502, 601); estimating, by the UE, a second SINR and a second CQI according to a received second downlink data frame (102, 302, 402, 504, 602), wherein the second downlink data frame is sent by the base station at a second moment later than the first moment; calculating, by the UE, a MCS variation according to the first CQI and the second CQI, or according to the first SINR and the second SINR, or according to the first CQI, the second CQI, the first SINR and the second SINR (103, 504, 605); and feeding back, by the UE, the MCS variation to the base station (104, 306, 405, 505, 607); wherein the base station adjusts a MCS used for transmitting a third downlink data frame according to the MCS variation (506, 609), the third downlink data frame is sent by the base station at a third moment later than the second moment; wherein the method further comprises: feeding back, by the UE, a downlink Hybrid Automatic Repeat Request, HARQ, result and the second CQI to the base station; compensating, by the base station, a SINR corresponding to the second CQI according to the downlink HARQ result, and obtaining a MCS used for transmitting a third downlink data frame by adding the compensated SINR and the MCS variation. receiving, by a user equipment, UE, a first downlink data frame sent by a base station at a first moment, and estimating a first Signal to Interference and Noise Ratio, SINR, and a first Channel Quality Indicator, CQI, according to the first downlink data frame (101, 301, 401, 502, 601); estimating, by the UE, a second SINR and a second CQI according to a received second downlink data frame (102, 302, 402, 504, 602), wherein the second downlink data frame is sent by the base station at a second moment later than the first moment; calculating, by the UE, a MCS variation according to the first CQI and the second CQI, or according to the first SINR and the second SINR, or according to the first CQI, the second CQI, the first SINR and the second SINR (103, 504, 605); and feeding back, by the UE, the MCS variation to the base station (104, 306, 405, 505, 607); wherein the base station adjusts a MCS used for transmitting a third downlink data frame according to the MCS variation (506, 609), the third downlink data frame is sent by the base station at a third moment later than the second moment; wherein the method further comprises: feeding back, by the UE, a downlink Hybrid Automatic Repeat Request, HARQ, result and the second CQI to the base station; compensating, by the base station, a SINR corresponding to the second CQI according to the downlink HARQ result, and obtaining a MCS used for transmitting a third downlink data frame by adding the compensated SINR and the MCS variation. feeding back, by the UE, a downlink Hybrid Automatic Repeat Request, HARQ, result and the second CQI to the base station; compensating, by the base station, a SINR corresponding to the second CQI according to the downlink HARQ result, and obtaining a MCS used for transmitting a third downlink data frame by adding the compensated SINR and the MCS variation.