Internet of things (IoT) is a way of connecting everything around us together, which would be widely applied in the 5G era. Narrow band IoT (NB-IoT) is one of the solutions introduced from 3rd Generation Partner Project (3GPP) Release-13 to fulfill this concept. Massive-connection and narrow band operation are two key features of NB-IoT. With current NB-IoT design, certain resources within narrow band are dedicated for transmitting paging information of massive connections. This leads to overload of the dedicated resources, and consequently increased padding bits and low resource efficiency. Moreover, UE power consumption would also rise due to the extra effort to decode larger packets. To solve above problems, a new resource allocation method is proposed, which includes a new definition of paging resource set and corresponding resource selection method. Link level simulation is conducted to show the benefit of our proposals. It is observed that approximately power consumption could be saved by 80% and the resource efficiency could be improved by 30.5% by utilizing our proposed methods.