In the progress of standardization of 3GPP Long Term Evolution (LTE), it is of the most importance to ensure the coexistence between LTE system and other systems. This paper is aiming at presenting a clear is deployed co-existed with TD-SCDMA system, which has been deployed in China. Monte Carlo simulation is used to get the statistic results. The two systems are assumed to have similar uplink and downlink ratio, i.e., there is no BS-to-BS interference. Adjacent channel interference power ratio (ACIR) model and interference model, which are the focuses of this paper, are modified to accommodate to the coexistence of TD-SCDMA and LTE-TDD systems. Capacity loss and throughput loss as the performance indicators are discussed in detail with three different system offsets. What's more, some useful conclusions on the coexistence of LTE-TDD and TDSCDMA systems are presented.