Abstract: Three freezing methods were used for comparison in our experiment of cooling rabbit skin, i.e. the methods of self-pressurized spray of liquid nitrogen(SSLN),liquid nitrogen closed cycling cryoprobe(LNCC)and pre-cooled probe(a largefreezing.capacity cylinder of certain solid materials with insulated handle, after dipping into liquid nitrogen used as a "cryoknife") (PSC).The PSC was depeloped by the author.