A method and apparatus are disclosed from the perspective of a UE. In one embodiment, the method includes receiving a signalling from a network node to trigger a non-contention based random access procedure, wherein the signalling includes a first information indicating a first numerology and a second information indicating a second numerology (2605). The method also includes transmitting a random access preamble based on the second numerology to the network node (2610). The method further includes receiving a random access response from the network node (2615). In addition, the method includes monitoring a control channel for scheduling a new transmission based on the first numerology (2620).