Dear all, using STM32F030C8 embedded system memory bootl-oader, why the micro-controller immediately reset after jumping to the system memory boot-loader then enters the application again ?

Probably because VTOR is still pointing to the program. Before jumping to system memory boot-loader , a lot of things need to be unset. It is easier to set some mark e.g. in uninitialized RAM, do a real reset and check at the beginning of the startup code if that mark is set. If set, unset mark and jump to bootloader.

Pretty sure the F0 doesn't have a VTOR to change, you have to remap the ROM properly and turn off all you interrupting sources.

#MillionWaysToFail