In this paper, a QoS (Quality of Service) multicast routing scheme in NGI (Next Generation Internet) is proposed based on genetic engineering and microeconomics. It can not only deal with network status inaccuracy, but also help prevent network overload and meet with intra-group fairness, trying to find a multicast routing tree with bandwidth, delay, delay jitter and error rate satisfaction degree, bandwidth availability degree and fairness degree achieved or approached Pareto optimum.