This study was carried out at Marmara Animal Research Institute in 1998-1999. The aim was to investigate the improvement in lamb production achieved by the use of Turkish Merino rams as a father line for the production of two-way and three-way crossbred slaughter lambs, together with intensive fattening programs. In this first part of the study, the fertility of ewes and the survival and growth characteristics of lambs were taken into consideration. For the fertility characteristics of Kivircik, Chios x Kivircik (F1) and Turkish Merino ewes mated with Turkish Merino rams, conception rates were 75%, 88% and 93.33%, litter sizes were 1.33, 1.41 and 1.36 and lamb productions were 1.00, 1.24 and 1.27, respectively. Two-way crossbred, three-way crossbred and Turkish Merino lambs had survival rates at weaning (day 90) of 92.86%, 100% and 100%, birth weights of 4.70 kg, 4.50 kg and 4.98 kg and weaning weights of 27.35 kg, 26.84 kg and 28.78 kg, respectively. The results determined in this study showed that the use of Turkish Merino rams as a father line in the production of two-way and three-way crossbred slaughter lambs did not have negative effects on fertility and survival characteristics, and lambs showed fast growth until weaning and reached the appropriate weight early enough for the beginning of fattening.