A wireless charging transmitter for a portable electronic device is provided. The wireless charging transmitter includes a first housing, a second housing and a wireless charge transmitting module. The wireless charge transmitting module is disposed within the second housing. The second housing is rotatable with respect to the first housing, so that either an included angle is defined between the second housing and the first housing or the second housing and the first housing are folded together. Whereas, in a case that an included angle is defined between the second housing and the first housing, once a wireless charging receiver is contacted with the second housing, electric power may be transmitted to the wireless charging receiver. In a case that the second housing and the first housing are folded together, the wireless charging transmitter has a rectangular shape. Due to the rectangular shape, the wireless charging transmitter is easily carried.