Taking fuzzy  retrieval for Chinese title catalogue as an example, this paper analyses  the fuzzy  retrieval problem for MARC and  proposes an improvement solution based on set operations. It splits the title for retrieval to metacharacters by fine-granularity and retrieves these metacharacters as redundant title for retrieval,then converges all retrieve results by set operations and returns. The improvement solution can enhance the depth to fuzzy retrieval  for MARC and optimize present retrieval system with low-cost.