An explicit finite element-finite difference method is performed to evaluate the part-projecting topography effects on the seismic response of visco-elastic sites. The different spectrum properties under the conditions of different high-width ratios （H/L value） and different angles of incidence are compared, the effect of multi-mesa is analysed also, The results show that for pres- ence of part-projecting topography, the H/L value and the direction of incident waves significantly affect the spectrum property, the effect of the direction of the incident wave is especially remarkable, the presence of multi-mesa also increases the amplification effect of sites.