Biofuel market in Poland grows rapidly. The main biofuel crop - rapeseed is designed for biodiesel production. However, there are no detailed assessments of greenhouse-gas emissions for cropping systems in Poland. Growing bioenergy crops and production of biofuels give an opportunity to achieve greenhouse-gas offsets. Proper quantification of net greenhouse gas fluxes can be performed through life-cycle analysis including all sinks and sources i.e. input of energy used for crop production, field greenhouse-gases emission, transport, fuel production, fuel displacement etc. The purpose of this work is to present greenhouse-gas balance by life-cycle assessment for bioenergy rapeseed crop grown in four years cropping system in different parts of Poland. Biogeochemistry model was employed for estimate quantification of field net greenhouse gasses emission.