A memory access monitoring method, comprising: performing coarse grain monitoring on local memory pages accessed by nodes of a system comprising said nodes and memories; storing, in a table entry of a coarse grain monitoring table, a count value of each counter corresponding to each node accessing a coarse grain page in the system, the coarse grain page is obtained by coarse grain dividing the local memory pages; determining, according to access amount by which each node in the system accesses a coarse grain page, whether a remote access rate by which the coarse grain page is accessed by a remote node exceeds a first predetermined threshold value: if yes, the coarse grain page is a hot page, and an operating system is requested to perform an optimized migration for the content of the hot page; otherwise, determining whether a total remote access rate by which the coarse grain page is accessed by all remote nodes exceeds a second predetermined threshold value: if yes, the coarse grain page is a half hot page, and a fine grain monitoring to the half hot page is initiated; and performing the fine grain monitoring on the half hot page, and if a hot area with the fine grain monitoring exists in the half hot page, requesting the operating system to perform an optimized migration for the content of the hot area. performing coarse grain monitoring on local memory pages accessed by nodes of a system comprising said nodes and memories; storing, in a table entry of a coarse grain monitoring table, a count value of each counter corresponding to each node accessing a coarse grain page in the system, the coarse grain page is obtained by coarse grain dividing the local memory pages; determining, according to access amount by which each node in the system accesses a coarse grain page, whether a remote access rate by which the coarse grain page is accessed by a remote node exceeds a first predetermined threshold value: if yes, the coarse grain page is a hot page, and an operating system is requested to perform an optimized migration for the content of the hot page; otherwise, determining whether a total remote access rate by which the coarse grain page is accessed by all remote nodes exceeds a second predetermined threshold value: if yes, the coarse grain page is a half hot page, and a fine grain monitoring to the half hot page is initiated; and performing the fine grain monitoring on the half hot page, and if a hot area with the fine grain monitoring exists in the half hot page, requesting the operating system to perform an optimized migration for the content of the hot area. if yes, the coarse grain page is a hot page, and an operating system is requested to perform an optimized migration for the content of the hot page; otherwise, determining whether a total remote access rate by which the coarse grain page is accessed by all remote nodes exceeds a second predetermined threshold value: if yes, the coarse grain page is a half hot page, and a fine grain monitoring to the half hot page is initiated; and if yes, the coarse grain page is a half hot page, and a fine grain monitoring to the half hot page is initiated; and performing the fine grain monitoring on the half hot page, and if a hot area with the fine grain monitoring exists in the half hot page, requesting the operating system to perform an optimized migration for the content of the hot area.