Abstract: Data cleaning technology was used to ensure the data quality of the system after data migration．Thus an interactive data migration system combined with data cleaning was proposed．The working principle of the system was then analyzed．By using the length filtration method in approximately-dupli cated-record detection‚the approximately-detecting algorithm was optimized to improve the detection efficiency．As a result‚the unnecessary editing distance computation was avoided‚which brings about an
improvement in the data migration speed of the whole interactive data migration system．Furthermore‚an appropriate experimental environment was created so that a lot of detection experiments could be carried out．Experimental results have proved the rationality of the length filtration method．

Key words: data migration, data quality, ata cleaning, approximately-detecting, length filtration