Quality adaptation using Scalable Video Coding (SVC) in Peer-to-Peer (P2P) Video-on-Demand(VoD) streaming In this paper we present novel quality adaptation mechanisms using Scalable Video Coding (SVC) over Peer-to-Peer (P2P) Video-on-Demand (VoD) systems. Quality adaptation in the VoD streaming system P2P is done in two phases. First using Layer Level Initialization (LLI) strategy, an initial quality is selected based on the peer’s static resources, for example screen resolution, bandwidth and device power. After streaming starts, another set of algorithms called the Layer Level Adjustment (LLA) is used to adapt the video quality to various dynamic parameters of the peers (memory, energy consumption) and the system (block availability, throughput). LLI and LLA are evaluated on Quality of Service (QoS) metrics of layer level SVC using Peersim and JSVM Simulators. Finally, we have ensured perfectly the best QoS for streamable SVC layers by our proposed algorithms which maximize flexibility SVC while taking impact of different resources consumption and affects resilience of P2P streaming systems into consideration.