The　intense　competition　for　survival　in　nature　for　billions　of　years　has　led　to　the　evolution　of　intricate　microstructures　in　biological　materials.　These　microstructures　break　the　well-known　strength-toughness　trade-off　of　traditional　structural　materials,　offering　new　ideas　for　developing　advanced　engineering　structural　materials.　However,　the　complex　microstructure　also　poses　a　new　challenge　for　classical　fracture　mechanics,　which　assumes　material　homogeneity.　The　macroscopic　fracture　behavior　of　biological　materials　exhibits　complex　features　of　multi-scale,　multi-process,　and　multimedium　coupling.　Studying　the　fracture　mechanics　of　biological　composites　with　microstructures　is　of　great　scientific　significance　and　has　potential　application　prospects　for　broadening　the　research　scope　of　fracture　mechanics,　promoting　the　development　of　fracture　mechanics　theory,　and　inspiring　the　optimization　design　of　advanced　structural　materials.　This　paper　reviews　recent　research　progress　on　the　fracture　mechanics　of　biological　and　bioinspired　composites　with　sophisticated　microstructures　from　three　aspects:　theoretical　analysis,　numerical　simulation,　and　experimental　techniques.　The　focus　is　on　introducing　new　methods　and　ideas　that　provide　guidance　for　the　development　of　fracture　mechanics　of　heterogeneous　materials　and　the　design　of　strong　and　tough　advanced　materials.　©　2024　Chinese　Academy　of　Sciences.　All　rights　reserved.