Method and apparatus for channel state information report for beam operation in a wireless communication system

A method and apparatus is described, from the perspective of the UE, for reporting channel state information (CSI). Preferably, the method includes a UE being configured with at least two CSI-RS (Channel State Information Reference Signal) resources (2505). Furthermore, the method includes the UE performing measurements on the at least two CSI-RS resources (2510). The method also includes the UE generating multiple CSIs according to measurements on the at least two CSI-RS resources, wherein at least one CSI corresponds to measurements on more than one CSI-RS resource (2515). The method further includes the UE reporting on at least one of the generated CSIs (2520).