The Center for Agricultural Research in Salamieh is interested in developing the livestock through its genetic improvement program. The Center is working on improving the genetic stock of sheep and selling sheep to farmers annually. The genetic improvement program is selecting sheep due to its milk production and the twin births percentages within three lines of breeding: meat line, milk line, and dual-purpose line. The study compared the three lines in terms of efficiency using the DEA method. The results of the analysis showed that the technical efficiency indicators for each of the three lines during the study period (2007-2014) confirm the superiority of the dual-purpose line in the efficiency indicators in case of constant return to scale. The dual-purpose line came first with an average technical efficiency of 84.1% followed by the milk line and the meat line as well. In case of variable return to scale, the arrangement was not different. The dual-purpose line came first with an average technical efficiency of 93.7%. Which confirms the results of the data envelope analysis to compare the performance of each line during study years, which showed that the technical efficiency of this line was more stable than the other two lines. The Technical Efficiency Index reached optimum efficiency in 2008 and 2012. This means that the genetic stock of sheep selected in this line is relatively better.