Abstract: The Infrared Atmospheric Sounding Interferometer (IASI) is a new-generation super-high-spectrum sounding instrument based on the Michelson interferometer and is loaded on the METOP-A European meteorological polar-orbit satellite. IASI covers multiple absorption bands to retrieve atmosphere, ocean, cloud, and atmosphere components to provide a wealth of remote sensing data for earth-atmosphere remote sensing, meteorological operations, and scientific research. Therefore, this instrument has gained increasing attention. To fully understand the applicability of IASI, a comparison is made in this study between the cloud top height products from IASI over Shouxian, Anhui Province, China, recorded from October 15 to December 15, 2008, and the cloud parameter information from W-band (95 GHz) Cloud Radar (WACR) supplied by the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) deployed in Shouxian. Within 20 km of AMF, a total of 129 measurements were synchronously made by the two instruments, 80 of which by IASI matched the data from WACR at the nearest distance. For the single-layer, the correlation coefficient and the standard deviations of the differences between IASI and WACR were 0.8312 and 1.8423 km, respectively. Moreover, for two- or three-layered measurements, the cloud top heights by IASI were, on average, within the WACR top and bottom cloud boundaries and close with thicker clouds. The comparison reveals that the cloud top heights by IASI are lower than by WACR in most cases. With increasing cloud cover, cloud thickness in the field of view, and the concentration of particles in the clouds, the result from IASI approach the true value.