This chapter introduces two kinds of memory management methods in Real Time-Thread (RT-Thread), namely dynamic memory heap management and static memory pool management. The RT-Thread operating system provides different memory allocation algorithms for memory management according to different upper-layer applications and system resources. There are two categories in general: memory heap and memory pool. The small memory management algorithm is mainly for systems with fewer resources and with less than 2MB of memory. The slab memory management algorithm mainly provides a fast algorithm similar to multiple memory pool management algorithms when the system resources are rich. The small memory management algorithm is a simple memory allocation algorithm. The memheap management algorithm is suitable for systems with multiple memory heaps that are not contiguous. The memory heap manager can allocate blocks of any size, which is very flexible and convenient. The memory pool control block is a data structure used by the operating system to manage the memory pool.