A center airbag cushion installed between left and right seats of a vehicle to protect a passenger from a shock generated by a side collision of the vehicle may include a first chamber part, a second chamber part comprising a left second chamber part and a right second chamber part respectively coupled to left and right sides of an upper end of the first chamber part to fluid-communicate therebetween, and a tension member provided on inner facing surfaces of the left and right second chamber parts, wherein the inner facing surfaces of the left and right second chamber parts face each other with a gap, and wherein the tension member has a rear end extending in a predetermined length rearwards and is fixed to a rear end of the first chamber part or the second chamber part therein.