For the R\'enyi's divergence with an index $\alpha$, 
we propose a criterion with respect to the index $\alpha$ 
on apportionment methods, which   
the criterion is the sum of the R\'enyi's divergence and 
a proposed function of $\alpha$ as a kind of penalty. 
Under the criterion, we also obtain appropriate house seats 
in the House of Representatives and the House of Councillors in Japan.