Injectable　in　situ　thermosensitive　hydrogels　have　potential　applications　in　tissue　engineering　and　drug　delivery.　The　hydrogel　formulations　exist　as　aqueous　solutions　at　room　temperature　but　rapidly　solidify　into　gels　at　37　degrees　C　in　situ,　making　them　highly　suitable　for　administering　drugs　in　a　minimally　invasive　manner　to　the　target　organ　(s).　The　hydrogel　formed　with　nanoparticles　assembled　with　amphiphilic　polymer　blocks　of　polyethyleneglycol　(PEG)　and　biodegradable　polycaprolactone　(PCL)　have　been　tested　as　platforms　for　targeted　and　sustained　drug　delivery,　and　have　shown　encouraging　results.　In　this　review,　we　summarize　the　influence　of　the　molecular　weight,　PEG/PCL　ratio　and　functional　structure　of　hydrophobic　PCL　blocks　on　the　critical　gelation　temperature,　gelling　behavior　and　drug　release　kinetics　of　the　hydrogels.　The　current　studies　on　the　biomedical　applications　of　thermosensitive　PEG/PCL　hydrogels　have　also　been　discussed.