The present invention discloses a method of using memory allocation to address hot and cold data, which comprises steps: using a hardware performance monitor (HPM) to detect at least one read/write event of a central processor; while a number of the read/write events reaches a threshold or a random value, a computer system recording an access type of the read/write event occurring latest and a memory address causing the read/write event; and the computer system assigning the memory object in the memory address to a volatile memory or a non-volatile memory according to the memory address and the access type. Thereby, data pages can be assigned automatically according to the access types categorized by the central processor, exempted from being assigned manually by engineers.