Malimasha is a kind of ancient minority characters merely used by about 100 people in Tacheng Town, Weixi County, Yunnan Province. According to its motivation, its origin and formation can be elucidated. Malimasha is not a branch generally acknowledged by some scholars, but rather a variable of Naxi writing. Only a few Malimasha characters were created by the local Naxi people, which mainly belong to pictographic or self-explanatory characters, and no pictophonetic characters have been found. Moreover, just a very few characters came from Chinese or Tibetan characters. Such an elucidation may have a reference value to the issue of loanwords in the study of character spread.