The emergence of the IoT, 5G and different modes of computing has introduced a new demand to tailor-made networks to support a wide spectrum of applications. Even though virtualizing networks and applying QoS to these networks are crucial, it is always challenging to achieve QoS, high acceptance ratio, and cost effectiveness on provisioning virtual networks given the constrained resource of the underlying network. This paper introduces Delay Constraint Optimum Bandwidth Tree (DCOBT), which effectively satisfies the QoS requirement of virtual networks in terms of both end-to-end delay and bandwidth. We propose the QoS-aware Resource Provisioning (QRP) algorithm to determine DCOBT with less bandwidth consumption and superior load balancing. Using SDN as a key platform to implement QoS-aware virtual networks, this paper further proposes flow rule reduction using Destination Label Forwarding (DLF) to provision more virtual networks with less Ternary Content-Addressable Memory (TCAM) consumption. The evaluation results proved significant contribution on different aspects of resource provisioning for QoS-aware virtual networks with improved availability, scalability, and cost effectiveness. © 2018 IEEE.