Abstract: Phenolic foam (PF) was prepared by using thermosetting phenolic resin as a raw material, p-toluenesulfonic acid as a curing agent and epoxy resin as a modifier. Effect of the amount of epoxy resin on the properties of PF was investigated. The results indicated that the apparent density, compression strength, thermal conductivity and pH value of PF were all improved due to the modification of epoxy resin. When the amount of epoxy resin was increased from 2 wt % to 8 wt %, the modified PF exhibited a decreasing trend in apparent density, thermal conductivity and degree of powder but an increasing trend in thermal stability and pH value. However, its compression strength increased at first and then tended to decrease. The modified PF achieved the maximum comprehensive properties when 6 wt % of epoxy resin was introduced.