Abstract. Maize is a thermophylic and hydrophilic crop. In the region of IASS "Obraztsov Chiflik"-Rousse temperature conditions are favorable for its cultivation, and precipitation and its distribution during vegetation proved to be a limiting factor. The objective of the study was the contrasting influence of the agro-climatic conditions on the mass of 1000 seeds, hectoliter mass and germination of RL 61/31 and H-108 lines to be determined in relation to their seed production and as donors of valuable genes in breeding. The experiment was conducted at the Experimental field of IASS "Obraztsov Chiflik"-Rousse during the period 2006-2008. It was designed after the Block method, in four replications. The results obtained showed that mass of 1000 seeds, hectoliter mass and germination in both lines were the lowest in the year with significant drought. Germination in both lines was strongly influenced by the agro-climatic conditions.