A coexistence communication method for broadband power line communication that allocates a resource of another heterogeneous system to a blank resource in data where a plurality of heterogeneous systems are allocated to time division multiplex units (TDMUs) in a distribution scheme and a system therefor are provided. The method includes detecting a blank resource according to a heterogeneous system which does not share a power line among a plurality of heterogeneous systems, from data in which the plurality of heterogeneous systems which share the power line to perform power line communication are allocated to a plurality of TDMUs and in which each TDMU is allocated to a plurality of time division multiplex slots (TDMSs) sorted over time in a distribution scheme and allocating added another heterogeneous system to the blank resource.