Porous silicon carbide ceramics with high porosity were prepared at low temperature by using ternary system Al 2 O 3 -Y 2 O 3 -SiO 2 as sintering aids of SiC powder，graphene，starch and flake graphite as pore forming agents．The effects of pore forming agents on the bulk density，porosity and bending strength of porous silicon carbide ceramics were discussed．The phase composition and microstructure of porous silicon carbide ceramics were analyzed．The results show that:(1)The pore forming effect of graphene in this system is better than that of starch and flake graphite，and the bending strength of porous SiC ceramics with graphene as pore forming agent is higher than that of porous SiC ceramics with flake graphite as pore forming agent，and lower than that of porous SiC ceramics with starch as pore forming agent．(2)Porous SiC ceramics sintered with different pore forming agents at 1 400 ℃ have a porosity of 53．34%～56．82% and a flexural strength of 14．86～17．47 MPa． (3)The use of different pore forming agents did not change the phase composition of silicon carbide ceramics．