Polyester fiber consisting of an aliphatic polyester having a melt viscosity of 1.0x102-1.0x104 poises at a temperature of 190 DEG C. at a shear rate of 1000 sec-1 and a melting point of 70-190 DEG C. The polyester fiber of the present invention exhibits biodegradability when buried in the ground. The amount of combustion heat generated on incineration is smaller than that of polyethylene and polypropylene. The polyester fiber of the present invention has excellent physical properties.
