Experiments were conducted to investigate the effect of injection times and particle sizes on particle transport in porous media. Two experimental series were performed under two different flow velocities. Injections of 392 mL particle suspensions into the porous media were repeated 13 times for each experimental series. The study reveal that injection times, particle sizes and seepage velocities have great impact on the characteristics of particle transport. Under steady seepage velocity, the transport curves of the injected particles have a normal distribution and the pore volume corresponding to the descent portion of the curve is larger than the value of ascent portion. Besides, the peak concentrations increase with injection times for low flow velocity conditions. However, peak concentrations hardly vary with the injection times for high flow velocity conditions. The amount of the deposited particles decreases with increased depth for particles of 3. 40 μm median diameter. The quality ratio of the deposited particles under 0. 085 cm/s flow is greater than those under 0. 170 cm/s flow. When the seepage flow rate is low, the effect of gravity increases for larger size particles, and the corresponding particle transport velocity is also higher. However, when the seepage flow rate is high, particle transport velocity is mainly controlled by hydrodynamic forces. The screen effect on particle deposition is more obvious for particles of larger grain sizes, resulting in a higher deposition rate.