In the atmosphere, clouds act as a medium where gaseous and particulate phase substances can react to alter the composition of atmospheric organic matter (AOM). To investigate the composition of AOM in cloud water, samples of supercooled clouds were collected at the Storm Peak Laboratory in Colorado (3220 m asl). AOM was isolated using a reverse phase extraction procedure and analyzed by electrospray ionization ultrahigh-resolution FT-ICR mass spectrometry. Chemical formulas for more than 5000 individual masses were assigned in the range of 100- 800 u. The AOM compounds contained a wide number of species with organic nitrogen and organic sulfur. The most abundant compounds were the ones with carbon number 1-20, with DBE range 0-6. The oxidation state of carbon for AOM compounds ranged from -2 to 3 with a mean value of -0.32. The exact masses and identified chemical formulas of cloud water AOM will be presented.