This paper focuses on the problem of conducted electromagnetic interference(EMI) in multi-load magnetic resonant wireless power transfer(WPT) system. A high frequency equivalent model is established to analyze the common mode(CM) and the differential mode(DM) conducted EMI by simulations in Saber. The comparison of CM interference has been made when the number of loads changing and the load impedances becoming unbalanced at the primary side. The circulation of the CM interference at the load side between two loads by coupling capacitors of resonant coils have been discussed. Filtering methods are put forward for multi-load magnetic resonant WPT system to reduce the CM interference. Both simulations and experimental results verify the complexity of EMI conditions and the significant effect of the filter.