Abstract: Selection response and genetic parameters for intramuscular fat (IMF) of breast muscle on 90 days were studied by analyzing the data from a selection experiment in a quality chicken line. Data had been collected over 4 generations (G0-G4) of selection. Genetic parameters of meat quality trait were estimated using MTDFREML software with animal model (N=632-1 084). From G0 to G4,the average IMF of chickens showed a continuing increase ,the mean of phenotypic value in G0 and G4 were 3.25±0.96% and 3.83±0.83% respectively. The coefficient of variation (C.V.) of G0 and G4 were 29.59% and 21.72% respectively. The estimated heritability and realized heritability (mean of 4 generations) of IMF was 0.220 and 0.322 respectively. A positive genetic correlation was observed between IMF of breast muscle and IMF of leg muscle, abdominal fat weight, abdominal fat percentage, width of fat strip, thickness of caudal skin and fat, thickness of comb, highness of comb and bodyweight of 90 days. The selection experiment demonstrated that IMF trait could be increased with selection through linebreeding.