Heterogeneous network (Het-Net) is part of the long-term evolution advanced (LTE-A) study item and represents cellular deployments with a mixture of cells of different overlapping coverage areas,e.g.,a number of relay and pico cells overlaid by a macro cell in the same frequency.Traffic balancing and interference management are required in Het-Net design for LTE-A to maintain system performance.In this paper,we propose an inter-domain cooperative traffic balancing scheme focusing on reducing the effective resource cost and mitigating the co-channel interference in multi-domain Het-Net.We first set up the conception of multi-domain in Het-Net and incorporate the co-channel interference into the proposed traffic balancing scheme.Then we model the traffic balancing issue as a multi-domain traffic resource optimization problem for minimizing the effective resource cost.The detailed implementation for the proposed traffic balancing scheme is designed.In the numerical evaluation,the genetic algorithm (GA) as an optimization method is used to demonstrate that the total effective resource cost is significantly reduced through our proposed inter-domain traffic balancing scheme,comparing with the intra-domain traffic balancing scheme.The 43％ of the resource cost is saved.In the system level simulation,the performance results of signal interference noise ratio (SINR) and throughput demonstrate that the proposed scheme has great advantages in interference management in Het-Net.