Squid　skin,　often　discarded　as　processing　by-product,　is　a　good　resource　of　collagen/gelatin.　In　this　study,　acid　soluble　collagen　(ASC),　pepsin　soluble　collagen　(PSC)　and　water　soluble　gelatin　(WSG)　were　extracted　from　squid　(Dosidicus　gigas)　skin　and　physicochemically　examined.　The　lowest　yield　of　33.5%　was　obtained　for　ASC　extracted　at　4 °C,　and　the　addition　of　pepsin　increased　the　collagen　yield　by　around　35.0%　(PSC).　The　highest　yield　of　81.9%　(WSG)　was　achieved　by　thermal　extraction　at　60 °C.　A　low　temperature　can　largely　retain　the　native　helix　structures　of　ASC　and　PSC,　contrariwise,　thermal　treatment　converted　collagen　into　gelatin　with　unordered　and　renatured　structures.　The　proline　and　hydroxyproline　contents　of　ASC,　PSC　and　WSG　were　183/1000　residues,　194/1000　residues　and　175/1000　residues,　respectively.　In　addition,　WSG　showed　a　denaturation　temperature　at　80.7 °C　which　was　much　higher　than　that　of　ASC　(24.2 °C)　and　PSC　(26.2 °C),　while　a　significant　lower　resistance　towards　enzymatic　digestion.　©　2021　Institute　of　Food　Science　and　Technology