Abstract: The New Jersey Meadowlands Commission has been monitoring ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2) and carbon dioxide (CO2) since 2007. These pollutants except CO2 are part of the principal pollutants that pose significant impact on human health established by USEPA. State of New Jersey and the federal government have set concentration standards for these principal pollutants to protect the public health and prevent environmental damage. The goals are to compare the data with the established standards, to determine the impact of major pollution sources, to measure background levels and to measure secondary impacts in rural areas. Samples are collected by Thermo Scientific five i-series gas analyzers at MERI’s roof for 24 hours a day. We examined the datasets of CO2, O3 and NOx and conducted the statistical analysis of the datasets. From the preliminary analysis summary we found in general the patterns are similar for CO2, NO2, NO, and NOx with respect to the season, day of the week, and the time of day. The patterns for O3 are different from those for the above 4 pollutants.