With the rapid development of building groups， the low-frequency microvibration caused by running metro train has be? come a serious problem. Aiming at a practical building group in Chengdu， the influences of running train on soil vibration and build? ing vibration are investigated. A detailed train-track-tunnel-soil-building group coupled dynamic model is established by considering the nonlinear wheel-rail dynamic interaction， the layered structure of soil and the soil-building interaction. A field test is conducted to study the source strength of metro system， which is also adopted to validate the dynamic model. On this basis， the train-induced soil vibration and local vibration at interface of different layers are studied. The influence of running train on building group is evalu? ated. Results show that， the established dynamic model is effective to solve low-frequency microvibration caused by running train. The predominant frequency of tested tunnel acceleration is 31.5~80 Hz， the VLzmax of tunnel wall is 70.3~71 dB， and the VLzmax of track bed is 94.3~125 dB. When the wave travels upwards in soil， the energy is absorbed while vibration nearby earth surface is amplified. Soil can absorb vibration above 80 Hz， and with the lateral distance increases，VLzmax decreases linearly. The train-in? duced building vibration is not beyond the limit values. Conclusions provide vibration control theory for building groups.