In hatcheries, the majority of males are killed shortly after hatching as they are considered waste, which is wasteful. Meanwhile, the interest of consumers in products from alternative systems (organic, free-range) is increasing. Stemming from the above fact, we had a idea that is to use one-day-old males, which continue to be raised freely to produce good quality chicken. This study was carried out at Hai Yen farm, Thai Nguyen province on 2 broiler Saso chicken lines: low-weight line (SA51) and heavy-weight lines (SA31), 150 male one-day-old chicks each line (5 repeats) reared in captivity to 21 days with density 6 birds/ m2, then free range reared in the garden with natural grass and fruit tree with density 5m2/ bird, monitor up to 90 days of age. The aim of this study was to evaluate the performance and compare the meat quality of two broiler lines at 49 and 90 days of age. The result as followed: Live weight, carcass yield, breast meat yield and the proportion of abdominal fat were significantly higher (P < 0.001) in SA31 at both ages. The proportions of fat in the breast meat were significantly lower (P < 0.01) in SA51 at both ages. The value of pH 24 h was significantly higher in SA51 and the meat was darker (P < 0.001) in these chickens. The overall acceptability was significantly better (P < 0 01) in SA51 at 90 days of age. The males are acceptable for an alternative system of poultry meat production from the aspect of meat quality.