Native chickens are important in some rural areas. They usually produce meat and eggs without extra feed using only picked food. Improving their economical traits, such production efficiency would save these genetic resources. Kianimanesh (2002) showed that age at sexual maturity, number of eggs, egg weight and body weight at 8th week of age are among most important traits for improving economical efficiency of Iranian native fowl. Although, natural selection is the great evolutionary force that fuels genetic change in all living things, selection at the long term has important responses such as increase of inbreeding and decrease genetic variation. However, changes in average of production traits and population response in breeding programs after a few generations of selections depended on accuracy and intensity of selection, effective size of population and the rate of inbreeding. The aim of this research was to study the rate of additive inbreeding on some of the economical traits in Fars native chickens in Iran.