This report gives a general presentation of the Québec energy system modelling realized through the MARKAL formalism, and aimed at the implementation of a system analysis methodology for energy policy assessment and long range technology evaluation. The report presents the MARKAL methodology, the model and data base improvements achieved within this research contract, and indicates the possible uses and future developments of the present model, which could lead to a model adapted to the multiregional structure of Canada. A quick presentation of a run of the model is provided. Two appendices show the level of details of the data base and of the output of a MARKAL run. A proposal for future work concludes the report.