Abstract: A portable apparatus having an electronic control system and a control method thereof are provided. The portable apparatus comprises an operation system, an accessing device and a basic input/output system (BIOS), and the electronic control system comprises a G-sensor and an embedded controller (EC) for initializing the G-sensor, wherein the G-sensor senses the acceleration of the portable apparatus and compares the acceleration value with the threshold value. The operation system comprises an application program (AP) and an advanced configuration and power interface (ACPI). When the acceleration value is higher than the threshold value, the G-sensor sends out a first signal to the EC, and the EC sends out a second signal to the BIOS, and the BIOS sends out a third signal to the ACPI, and the ACPI sends out a fourth signal to the AP to give a park command for parking the reading head of the accessing apparatus.