Abstract: Embodiments of the application provide method and system for defense against ROP attacks. The method comprises: identifying a substitutable instruction pair in a binary file, which includes a first instruction for pushing a first group of registers into a stack memory, and a second instruction for popping the first group of registers off the stack memory, generating an equivalent instruction pair for the substitutable instruction pair, which includes a first equivalent instruction for pushing a second group of registers onto the stack memory, and a second equivalent instruction for popping the second group of registers off the stack memory, wherein the second group of registers includes the first group of registers and at least one additional register which is not used by the substitutable instruction pair, and overwriting the first instruction and the second instruction with the first equivalent instruction and the second equivalent instruction respectively.