Objective　To　study　mechanical　properties　of　the　microstructure　of　the　articular　cartilage　with　biological　activity　by　nanoindentation　tests　under　the　condition　of　keeping　the　articular　cartilage　in　water.　Methods　The　different　abilities　to　keep　in　situ　mechanical　properties　of　the　articular　cartilage　with　cold　mosaic　method　or　with　moisturizing　method　were　evaluated　by　experiments,　and　the　mechanical　properties　of　the　microstructure　of　the　articular　cartilage　in　different　kinds　of　solution　used　in　moisturizing　method　were　also　obtained.　Results　The　experiment　showed　that　the　elastic　modulus　on　the　cartilage　surface　layer　with　cold　mosaic　method　was　much　higher　than　that　with　moisturizing　method,　and　the　elastic　modulus　on　the　cartilage　surface　and　deep　layer　in　chitosan　and　saline　were　much　lower　than　that　in　distilled　water.　Conclusions　The　moisturizing　method　is　better　at　preserving　in　situ　mechanical　properties　and　biological　activity　of　the　biological　materials,　and　chitosan　and　saline　are　proved　to　have　the　effect　of　keeping　mechanical　properties　of　the　cartilage　used　in　moisturizing　method.