The ministry's parliamentary state secretary, Christoph Bergner, signed a memorandum of understanding with Chun Sig Kim, South Korea's deputy minister in charge of reunification questions, outlining how Berlin might advise Seoul on reunification matters, a statement said.
Measures include the setting up of a committee of experts to look at how the German reunification model might be applied to Korea.
On Sunday Germany celebrates the 20th anniversary of its reunification after the end of the Cold War division of the country between communist East and capitalist West.
Korea was united until 1948 when it was split between communist North and capitalist South. This was followed by all-out war between the two states from 1950 to 1953.
"Of course we know that every country has its own historical and political conditions and characteristics. But we are willing to share our insight and experience as regards the resolution of the German question and the rebuilding of eastern Germany," Bergner said in a statement.