The present investigation was executed at two locations (El-Arish & (Rafah), Suez Canal University during rain-fed growing season (2006 / 2007) on screened ten bread wheat genotypes. Mean squares and some genetic parameters for the investigated characters are discussed. Grain yield was positively and significantly correlated with each of No. of spikes / plant under Arish conditions and 1000 grain weight as well as biological yield at both Arish and Rafah locations? . The main source (direct effects) of plant grain yield var-iation estimated under Arish conditions is 1000 grain weight followed by number of spikes / plant, number of grains /spike and biological yield. Estimates of characters re-sponsible for variation in order of relative im-portance were: number of spikes/plant (12.2%), No.of grains/spike (13.3%), 1000 grain weight (50.7%) and biological yield (17.5%) under Arish conditions while it could be arranged in descending order as 1000 grain weight (51.9%), number of grains / spike (45.5%), Number of spikelets / spike (1.4%) at Rafah environment.