diff --git a/Documentation/components/filesystem/tmpfs.rst b/Documentation/components/filesystem/tmpfs.rst
index 97a88bf3c5..95fda02cfc 100644
--- a/Documentation/components/filesystem/tmpfs.rst
+++ b/Documentation/components/filesystem/tmpfs.rst
@@ -2,4 +2,12 @@
 TMPFS
 =====
 
-TMPFS filesystem.
+NuttX TMPFS file system is a tiny dyamic RAM based file system. 
+
+It can be enabled by adding ``CONFIG_FS_TMPFS=y`` to the configuration at build time. 
+
+At runtime, simply use ``mount -t tmpfs /tmp`` to have a ``/tmp`` folder backed by TMPFS, then files and folders can be created under that folder. 
+
+Be aware that TMPFS is backed by kernel memory thus don't expect to store big files on it and its size is limited by free kernel memory.
+
+We can watch the size of TMPFS with ``df -h`` command, especially you can see the ``Size`` column of TMPFS changes when files are added or removed in the TMPFS folder. Changes in TMPFS size is always reflected by reverse changes of free kernel memory size.