In　this　paper,　we　consider　a　fear　effect　predator-prey　model　with　mutual　interference　or　group　defense.　For　the　model　with　mutual　interference,　we　show　the　interior　equilibrium　is　globally　stable,　and　the　mutual　interference　can　stabilize　the　predator-prey　system.　For　the　model　with　group　defense,　we　discuss　the　singular　dynamics　around　the　origin　and　the　occurrence　of　Hopf　bifurcation,　and　find　that　there　is　a　separatrix　curve　near　the　origin　such　that　the　orbits　above　which　tend　to　the　origin　and　the　orbits　below　which　tend　to　limit　cycle　or　the　interior　equilibrium.