POLYGRAM project was funded by the Natural Environment Research Council (NERC) with the grant number NE/V007149/1. POLYGRAM push the frontiers for CO2 and CH4 polyisotopologue measurement capability using the latest advances in laser spectroscopic analysis and high-resolution isotope ratio mass spectrometry. We establish a small global atmospheric sampling network to examine latitudinal and longitudinal variations in in polyisotopologues, to constrain overall global budgets of CO2 and CH4.