Metamaterial is an artificial, advanced material that has properties such as electromagnetic waves (EM), namely isotropic materials with permittivity and permeability in a single phase at a certain frequency. Smart magnetics is one of the metamaterials that is a modified magnetic material that has a single-phase permeability and permittivity as a function of frequency depending on the type of magnetic material used. Smart magnetics in this study include perovskite, ferrite, hexagonal ferrite, and composite systems. Research that has been carried out on perovskite, ferrite, hexagonal ferrite and composite smart magnetic system materials are La 0.8 Ba 0.2 Fe x Mn ½(1-x) Ti ½(1-x) O 3 , Ni x Fe 3-x O 4 , and Ba (1-x) Sr x Fe 2 O 4 , Ba 0.6 Sr 0.4 Fe 12-z Mn z O 19 and composite silicon rubber-iron oxide. The four smart magnetic material systems have an average microwave absorption in the X-band frequency range. Very varied reflection loss characteristics depend on the smart magnetic material system formed. It was concluded that smart magnetic material is a microwave absorbent that has reflection loss values in the X-band frequency range. Smart magnetic material is certainly not able to absorb microwaves on all band frequencies because each smart magnetic material has different resonance characteristics, so the maximum effort that can be done is to find the right composition of smart magnetic material which is expected to have the maximum wave absorption capability.