This study was carried out to investigate the effects of different seasons on growth performance of Konya Merino Lambs born March-April 1997 (control group of 80 heads) and December 1996-January 1997 (experimental group ol 63 heads) in Animal Research Institute in Konya. At birth, 1^st, 2^nd, 3^rd, 4^th, 5^th and 6 months of age, the lambs' weight were found as, 4.20, 10.11, 16.03, 22.13. 26.24, 29.59 and 32.58 kg in the control group and 4,23, 10.64, 17.26. 19.74, 23.03. 26,58 and 30,34 kg in the experimental group respectively. From the data obtained in this research, it was lound out that the seasonal effect on the lambs' growth trails was important at all stages of growth except lor that of birth weight. The effects of the litter size and sex on live weight were significant at birth, 1^st and 2^nd months of age. at the other stages of growth there was not. The effect of the mother age was important at only birth weight.