To provide an anchor agent excellent in the adhesion of a biodegradable film and biodegradable printing ink, in particular a polylactic acid film and ink containing polycaprolactone and/or esterified starch as a binder, and a biodegradable laminate using the anchor agent.

The anchor agent for the biodegradable printing ink is characterized by including an aliphatic polyester containing 90 wt.% or above of a lactic acid residue and characterized in that a molar ratio (L/D) of L-lactic acid and D-lactic acid is 0.05-19 and a reduced viscosity is 0.3-1.0 dl/g. The biodegradable laminate using the anchor agent is also disclosed.