We have fabricated various porous nickel aluminides with bi-modal pore size distribution by combustion synthesis reaction between Ni and Al with NaCl space holder powder. Effects of powder blending ratio in Ni+Al+NaCl powder mixture on porosity and size of small pores derived from the reaction. NaCl powder, which is a former of large pores, affects not only the large pores but also the small pores derived from the reaction between Ni and Al. Tendencies of change in porosity and size of the small pores with the amount of NaCl were different depending on Ni:Al molar ratio. The reason was discussed in shrinkage of volume of metallic cell wall due to the formation of nickel aluminides from Ni and Al mixture.