Each network has its own distinct quality of service (QoS) class. To support end-to-end QoS QoS class interwoking between different network technologies is very important function especially in Next Generation Networks (NGN). QoS mapping between different networks technologies are broadly categorized as mapping between parameters and mapping between classes in each different networks. However, these methods have some problems that the the former is too complicated to implement or the latter may execute uncetrain mapping between networks because of granularity QoS class.

So in this paper we present two QoS class mapping methodologies over heterogenous networks to provide end-to-end QoS support for application services. And we propose a QoS class mapping method in different transport techonologies mixed circumstance using Application Service Map (ASM) which classifies application services based on performance requirements. Ths mapping method is based on location information of ASM to determine QoS class according to underlying techonology. The proposed mapping method can easy to accept new coming application services without alternation or modification and it can provide users with the more refined QoS.