Increase of "greenhouse gases" level, rise caused by human activities, artificially accentuated greenhouse effect, resulting in increased global temperatures and disturbing climate. This paper analyzed the concentrations of several greenhouse gases recorded for Romania in the last years. The study is based on the existent data from European Environment Agency, Airbase. Annual average concentrations of the analyzed greenhouse gases exceeded the thresholds in many cities around Romania especially in highly industrialized centers and with large population.