There is no available adequate information on the biology and genetics of the Caspian salmon (salmo truta Caspiu) living in the Caspian Sea with other species such as common carp families, sturgeons and etc., therefore we are interested in knowing whether selection for rapid growth rate in salmo trutta Caspius will potentially lead to correlated genetic response in body weight and length. The potential for correlated responses was evaluated by the heritability estimation, estimating heritabilities of body weight and length. The genetic parameter estimations were obtained for different stages of growth from 5400 fish consisting 27 unrelated families that reached maturity at 36 months of age. The parent which used to produce separate family groups had been caught from the Caspian Sea and spawned during the autumn season. The estimated heritability of body weight and length was 0.42±0.13 and 0.49±0.01, respectively based on differential and selection response between parent pairs and their offsprings. Several factors may have affected the creation of this high level of estimation, dominant effect, inherited from different breeders to offspring.