Abstract: Provided is a method and apparatus for an adaptive context switching for a fast block input/output. The adaptive context switching method may include: requesting, by a process, an input/output device to perform an input/output of data; comparing a Central Processing Unit (CPU) effectiveness based on whether the context switching is performed; and performing the input/output through the context switching to a driver context of the input/output device, or directly performing, by the process, the input/output based on a comparison result of the CPU effectiveness.