This paper proposes a novel approach to
combinatorial test generation, which achieves an increase of not
only the number of new combinations but also the {\em distance}
between test cases. We applied our distance-integrated approach to
a state-of-the-art greedy algorithm for traditional combinatorial
test generation by using two distance metrics, Hamming distance, and
a modified chi-square distance. Experimental results using numerous
benchmark models show that combinatorial test suites generated by
our approach using both distance metrics can
improve interaction coverage for higher
interaction strengths with low computational overhead.