Abstract: A spectrum resource allocation scheme for improving the expected network throughput in tiered femto-cell networks was proposed. The scheme distributed partial shared spectrum resource to downlink transmissions in macrocell and femtocells. With the limitation that expected single-user throughput meets service of quality (QoS) requirement, the expected network throughput was maximized by adjusting the allocation ratio of shared spectrum resource dynamically. Furthermore, to obtain the per-tier expected throughput of downlink transmissions, the cumulative distribution functions (CDF) of received signal to interference plus noise ratio (SINR) were derived with Nakagami-m fading channels. Both theoretical analysis and simulations indicate that the resource allocation scheme improves the expected network throughput, but the degree of improvement is limited by the increase of QoS requirement parameter.