Partial meniscectomy was a common method of treatment for a meniscal injury and currently available instruments were scalpel, punch, electrocautery, CO2, laser, Nd: YAG laser, etc. However some methods could cause injuries to adjacent meniscal tissue after meniscectomy. An experimental study was conducted in order to examine the depth of injury to adjacent meniscal tissue according to above 5 different methods of meniscectomy. 25 medial menisci were harvested from Yorkshire pig knee immediately after the death of pig. Meniscal injury, 1.5cm long and 0.5cm wide, was made by using 5 different methods and was analysed macroscopically and microscopically. Average depth of injury was 237 in Nd: YAG laser group. 258um in electrocautery group, 307um in CO2, laser group, and nil in scalpel and punch group. The depth of meniscal injury of Nd: YAG laser and electrocautery group were less than that of CO2, laser group. Scalpel and punch were the most safe methods to adjacent meniscal tissue. CO2, laser, Nd: YAG laser and electrocautery should be carefully applied because they could cause the significant depth of injury in the adjacent meniscal tissue.