A method and apparatus are disclosed for handling multiple D2D grants for multiple sidelinks in decreasing order of priority. In one embodiment, the method includes a first UE participates in a first sidelink and a second sidelink, wherein a priority of the first sidelink is higher than a priority of the second sidelink. The method also includes the first UE receiving a first D2D grant and a second D2D grant from a base station in a first SA period. The method further includes the first UE serving the first sidelink with the first D2D grant and afterward, the first UE cannot serve the first sidelink with another D2D grant for the same SA period as the first D2D grant. In addition, the method includes the first UE serving the second sidelink with the second D2D grant and afterward, the first UE cannot serve the second sidelink with another D2D grant for the same SA period as the second D2D grant. Furthermore, the method includes the first UE using the first D2D grant for transmitting available data of the first sidelink and using the second D2D grant for transmitting available data of the second sidelink in a second SA period, wherein the second SA period and the first SA period are different SA periods.