I present the recent study on natural and unnatural SUSY in light of the proton decay and gauge unification. We show that the low energy SUSY mass spectrum is linked to the proton decay via the unification scale, and future nucleon decay experiments will provide a non-trivial upper bound on the superpartner masses. We also show that the mirage mediation provides a consistent picture of natural SUSY. For unnatural SUSY, we present a systematic study on split SUSY and predict a unique spectrum, which could be around the corner of discovery.