Calcium phosphate foam could be an ideal bone filler and scaffold for tissue engineering. This paper describes fabrication method of β-tricalcium phosphate (βTCP) foam with fully-interconnected porous structure by employing magnesium oxide (MgO) as βTCP stabilizer. The foam was prepared using the so-called ceramics foam method. MgO was added to calcium carbonate and dicalcium phosphate dihydrate so that 0, 1, 2, 3, 4, 6 and 8 mol% calcium would be substituted by magnesium (Mg) in βTCP structure. After sintering at 1500°C, crystal phase of the obtained foam included β-tricalcium phosphate (αTCP) when no Mg or less than 3 mol% Mg was added. In contrast, crystal phase was single phase βTCP when 3 mol% or higher Mg was added. The compressive strength was approximately 15 kPa and the porosity was above 95% for all specimens. No significant difference was observed between αTCP and βTCP foams in compressive strength and porosity when the sintering temperature was the same.