A biodegradable polymer blend contains at least one component (A), at least one component (B) and at least one component (D), wherein —component (A) includes polymers based on lactic acid —component (B) includes thermoplastic starch (TPS) representing a mixture of starch, at least one plasticizer from the group of substances (C), and at least one modifier from the group of substances (E); —group of substances (C) includes plasticizers for starch —group of substances (E) includes modifiers —component (D) includes homopolymers or copolymers of polyhydroxyalkanoates (PHAs), and/or mixtures thereof, and the biodegradable polymer blend can optionally contain a component (F), wherein —component (F) includes plasticizers for PLAs and/or for PHAs, and the biodegradable polymer blend is prepared in a such way that a composition containing the components (A), (B) and (D) is prepared by blending the components (A) and (B), wherein the component (B) is present in the blend at least in one phase of the blending process where at least one component (B) and at least one component (A) are blended concurrently, and this phase of the blending process precedes, by at least one phase, that phase of the blending process where the component (D) is added to the blend, and the optional components (F) and (G) can be added to the blend in any one or multiple phases of the blending process, and in one or several doses.