A Mobile Ad hoc NETwork (MANET), is a self-configuring infra structure less network of mobile devices connected by wireless links. ad hoc is Latin and means "for this purpose". Each device in a MANET is free to move ndependently in any direction, and will therefore change its links to other devices frequently. Each must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. QOS is defined as a set of service requirements to be met by the network while transporting a packet stream from source to destination. Intrinsic to the notion of QOS is an agreement or a guarantee by the network to provide a set of measurable pre-specified service attributes to the user in terms of delay, jitter, available bandwidth, packet loss, and so on. The analysis is mainly between proactive or table-driven protocols like OLSR (Optimized Link State Routing) viz DSDV (Destination Sequenced Distance Vector) & CGSR (Cluster Head Gateway Switch Routing) and reactive or source initiated routing protocols viz AODV (Ad hoc on Demand distance Vector) & DSR (Dynamic Source Routing). The QoS analysis of the above said protocols is simulated on NS2 and results are shown thereby.