Rolling bearing cages disclosed herein are prepared from compositions comprising an aromatic polyamide which comprises terephthalic acid constituent units, aromatic dicarboxylic acid constituent units other than terephthalic acid constituent units and straight-chain aliphatic alkylenediamine constituent units, and glass fibers, and can be easily incorporated into bearing races without damage, resultant bearings capable of being operated over a long period of time without deformation of said cages and deterioration of the lubricant oil.