Abstract: The present invention provides a biodegradable resin having an intrinsic viscosity of 1.0 dL/g or more, and having a loss rate of intrinsic viscosity of 10% or more after treatment at 70° C. and 85% RH for 6 hr. The present invention also provides a biodegradable resin containing 70 wt% or more of polylactic acid and having a relative biodegradation rate up to 90% or more within 12 months when the degradability in home composting at 28° C. is evaluated according to the conditions specified in ASTM D5338-15. The biodegradable resin has the characteristics of fast biodegradation speed and stable storage, has good mechanical properties, optical properties and barrier properties, can be applicable to various aspects including packaging and express transportation, and will quickly biodegrade into carbon dioxide, water and other small molecules without contamination to the environment at the end of service life.