The comprehensive development of urban over-track areas is promoting the intensive progress of metropolises， and thus there are numerous buildings with different structural types increasingly emerging above the metro depots in these cities. However， the interaction between subway vehicles and tracks may induce vibrations to affect the comfort in over-track buildings. It is necessary to perform a comparative study of vibration characteristics in over-track buildings with different structural types. The research subjects of this paper are the steel frame and reinforced concrete frame buildings in the Shanghai Xujing metro depot. Field tests are carried out in these two buildings with different structural types. Comparisons of vibration responses are performed using evaluation indexes including the Z vibration level， one-third octave plumb vibration level， total root-mean-square acceleration， etc. The results show that the vibration responses of the first story in these buildings are almost the same， while the responses of the mid and top stories of the steel building are larger than those of the reinforced concrete building. There are high-frequency （100~180 Hz） vibrations existing in the reinforced concrete building. Besides， their vibration responses meet the limits of different codes. To further improve the floor comfort of over-track steel buildings， the design thickness of the mid and top stories can be appropriately increased. This study can provide data support for the development of over-track buildings with different structural types.