AbstractThe ambient calculus and the P-systems are models developed in different areas of computer science. Still, they are based on similar concepts and structures and are inspired from the same natural model of computation [BeBo92]. On this basis, we point out how to transfer ideas and results from one framework to the other. We prove that any P-system can be simulated in ambient calculus. We also introduce the notion of mobile P-systems, suitable to model and motivate security features for membrane computing.