A data duplication device comprising: a range determination unit to determine a duplication range using a data processing graph indicating information of input/output data to and from a duplicate source program involved in a duplicate source system , the duplication range being a range of data to duplicate from the duplicate source system to a duplicate destination system ; a data acquisition unit to acquire duplicate data corresponding to the duplication range from the duplicate source system ; and a data registration unit to register the duplicate data with the duplicate destination system , wherein the data processing graph includes: a program node indicating the duplicate source program; an input information node indicating information of input data out of the input/output data to and from the duplicate source program; an output information node indicating information of output data out of the input/output data to and from the duplicate source program; a data range node indicating a data range of the input/output data to and from the duplicate source program; a table node indicating a duplicate source table involved in the duplicate source system ; and links to connect the program node , the input information node , the output information node , the data range node , and the table node . a range determination unit to determine a duplication range using a data processing graph indicating information of input/output data to and from a duplicate source program involved in a duplicate source system , the duplication range being a range of data to duplicate from the duplicate source system to a duplicate destination system ; a data acquisition unit to acquire duplicate data corresponding to the duplication range from the duplicate source system ; and a data registration unit to register the duplicate data with the duplicate destination system , wherein the data processing graph includes: a program node indicating the duplicate source program; an input information node indicating information of input data out of the input/output data to and from the duplicate source program; an output information node indicating information of output data out of the input/output data to and from the duplicate source program; a data range node indicating a data range of the input/output data to and from the duplicate source program; a table node indicating a duplicate source table involved in the duplicate source system ; and links to connect the program node , the input information node , the output information node , the data range node , and the table node . a program node indicating the duplicate source program; an input information node indicating information of input data out of the input/output data to and from the duplicate source program; an output information node indicating information of output data out of the input/output data to and from the duplicate source program; a data range node indicating a data range of the input/output data to and from the duplicate source program; a table node indicating a duplicate source table involved in the duplicate source system ; and links to connect the program node , the input information node , the output information node , the data range node , and the table node . <EOS>