MEMORY SYSTEM AND OPERATING METHOD THEREOF

A memory system may include a memory device including a plurality of planes each including a plurality of memory blocks; and a controller suitable for storing first and second command data corresponding to first and second commands in a first and a second sub-buffer of a buffer or one or more extra page buffers among page buffers included in the plurality of planes, respectively, according to a priority information and a size information of the first and second commands, and performing first and second command operations in response to the first and second commands, respectively.