Loess covers most areas of Khon Kaen University campus, northeastern Thailand. It is identified as a collapsible soil. This study aims to find the engineering properties of loess using multi-channel analysis of surface wave (MASW) and downhole seismic methods. MASW results show that the shear wave velocity varies from 242 to 329 m/s while the compressional wave velocity is 371 to 740 m/s. The results of downhole method show that shear wave velocity ranges between 210 and 323 m/s, while the compressional wave velocity varies from 420 to 771 m/s. The derived body wave velocity from MASW method varies by 25% from that obtained using the downhole method. Young's modulus calculated from these results was validated with information from previous research and larger than those of determining via static geotechnical tests. The MASW method is a relatively costeffective method, so it can be applied as an alternative to geotechnical testing when determining soil elastic properties.
