A wireless power transmission apparatus including a controller configured to perform a negotiation for a first available power indicator with a wireless power reception apparatus; and a power converter configured to transmit a wireless power to the wireless power reception apparatus according to the first available power indicator. The controller transmits, to the wireless power reception apparatus in response to a received power packet, a bit pattern response requesting a communication by the wireless power transmission apparatus to change the first available power indicator, and transmits a packet related to a second available power indicator to the wireless power reception apparatus. Further, the bit pattern response is composed of 8 bits, and the bit pattern response is defined as a different pattern from a bit pattern for an 8-bit ACK response, an 8-bit NAK response and an 8-bit ND response.