Provided are method and apparatus for dynamically allocating unlink bandwidth in Ethernet PON. In the method and apparatus, report value, which are received for each logical link identifications (LLID), is controlled to be less than a maximum gate value set for each LLID in sequence for all of LLIDs without a predetermined interval. A gate having a length corresponding to the restricted report value is generated. LLIDs are grouped into classes and processing is done class by class. For each class processing, if maximum processing time is reached or maximum total allocation is reached, the processing is switched to a lower class. Also each class processing, if any higher class has its maximum yield processing time or maximum yield allocated gate reached, the processing is switched to that higher class.