(I am assuming that you are looking this information because of interoperability, so providing my response accordingly)
Each bearer (user data) path in LTE is assigned a set of QoS criteria. In the case a user may have services requiring different QoS criteria, additional bearer paths may be added. LTE identifies a set of QoS criteria with QoS Class Identities (QCIs). These are listed in following figure.
The critical QoS parameter for any EPS bearer is its QCI, which represents the QoS features an EPS bearer should be able to offer for a Service Data Flow (SDF). Each SDF is associated with exactly one QCI. Network operators may pre-configure all QCI characteristics in an eNB, for example, based on their actual characteristics. The parameters they choose to define these determine the allocation of bearer resources in the E-UTRAN.
LTE and UMTS employ different QoS mechanisms, we need to be able to map between LTE's QCI parameters for EPS bearers and the four QoS categories and associated parameters of Pre-Release 8 PDP Contexts. For 3G subscribers, the broadband gateway converts the traffic class to a QCI, based on the 3GPP specification 23.401 ANNEX E.
Please let me know if it clears the doubt...