In　this　work,　we　study　the　impacts　of　different　types　of　strain　relief　layer　(SRL)　on　dynamic　on-resistance　(R　(on))　degradation　of　GaN　power　devices　on　Si　by　back-gate　ramping　and　vertical　leakage　measurement.　Our　study　reveals　that　the　SRL　has　important　effects　on　the　dynamic　R　(on).　Compared　with　step-graded　AlGaN　SRL,　the　superlattice　SRL　possesses　much　more　energy　barriers,　which　can　more　effectively　block　the　leakage　of　holes　from　GaN　buffer　and　the　injection　of　electrons　from　Si　substrate.　Enhancing　the　carrier　blocking　ability　of　SRL　could　contribute　to　the　suppression　of　dynamic　R　(on)　degradation.