The cavity is one of the basic structures in pipe systems, but it is vulnerable in erosive environments. Cavities can occur in various places throughout industrial processes, each making a difference in the distribution of erosion. The aim of this study is to investigate gas (air)-solid flow properties and erosion characteristics in inclined cavities. A two-way URANS (SST)-DPM method was adopted. The simulations were carried out for three Stokes numbers (St), eight height differences (h) from 0 to 0.8H, and ten inclination angles from 0 degrees to 90 degrees. Results indicated that gas flow properties change little with inclination angle (phi). However, a variation in phi resulted in a change in the distribution of the particles and erosion on the aft wall, especially when St were 1.2 and 9.1. The particle number (N) in the zone 10 mm from the aft wall decreases linearly with phi for both previously mentioned St, and the slopes of N-phi curves increase exponentially with h. The maximum erosion rate (E-m) on the aft wall also decreases linearly with phi for the St of 12, and the negative slope of E-m-phi curve follows an exponentially increasing with h. But Em decreases quadratically with phi when St is 9.1, and the function coefficient appears a Gaussian relationship with h. (C) 2016 Elsevier B.V. All rights reserved.