Disclosed are a polysiloxane-modified polylactic acid resin, composition using same, molded article, and production method, whereby it is possible to produce a molded article via a simple method, and where said article may be used in applications demanding a high level of impact resistance as an alternative to ABS resin or the like, has a similar level of impact resistance as said substances, has superior flexibility with respect to rupture bending strain and tensile breaking strain, and has bleed resistance. The polysiloxane-modified polylactic acid resin has a segment which is a polylactic acid compound, and a segment which is an amino polysiloxane compound which has an amine group. With respect to the amino poly-siloxane compound, amine groups are on average contained in the range of 0.01 to 2.5% inclusive by mass, and with respect to the polylactic acid compound, are on average contained in the range of 3 to 300 ppm inclusive by mass.