A biodegradable resin composition and an object molded or formed from the composition. The resin composition comprises: 100 parts by weight of a biodegradable polyester resin comprising not smaller than 50% by weight of polylactic acid having a melting point of not lower than 160.degree. C., the biodegradable polyester resin having a melt flow rate of 0.1 to 50 g/10 min as measured under a load of 21.2 N at 190.degree. C.; and 0.1 to 20 parts by weight of a phyllosilicate containing a primary, secondary or tertiary amine salt, a quaternary ammonium salt or a phosphonium salt ionically bonded between layers thereof.