Abstract: The random finite element method (RFEM), which incorporates simulation techniques of random fields with the finite element method, is proposed to analyze the seismic response of rockfill dams. In order to consider the spatial variability of dam materials, a Local Averaged Subdivision method is used to simulate the random physical and mechanical property fields. Moreover, to lower the cost of obtaining statistical information of mechanical properties of materials, it is suggested to adopt constitutive equations which connect mechanical properties with physical ones. Then, the random seismic response and deformation of a real rockfill dam is simulated via RFEM, in which the dry density, void ratio, median grain size, uniformity coefficient, initial internal friction angle and shear modulus coefficient of the rockfill materials are modelled as random fields. The simulated results show that: (1) The randomness of dam materials will induce unneglectable dispersion in the performance of dams; (2) It is very likely that the response of dams will be underestimated if the randomness of dam materials is overlooked; (3) Some dynamic performance indicators may follow neither the normal nor the lognormal distribution.