Based on blasting vibration monitoring for the second phrase for Ling-ao Nuclear Power Station in Guangdong Province，the wave propagation characteristics under blasting in concave landforms are simulated with UDEC. It is founded that the numerical simulation results agree well with that by site monitoring. It is reported that the peak particle velocity (PPV) of blasting clearly decreased in concave landforms and the decreasing rate of PPV in horizontal direction is large than that in vertical direction. It is also reported that the attenuation coefficient increased with increment of depth and width of concave landforms; and the rising rates of attenuation coefficient with the width is less than that of depth. It is further suggested that the attenuation coefficient increases with increment of the charge weight and decreases with increment of explosive distance.