It is possible to switch between the different aggregation phenomena of deoxyribonucleic acid (DNA)-conjugated poly(N-isopropylacrylamide) (PNIPAM) by controlling the balance of DNA charges and flexibility. The shift in the balance between DNA charges and flexibility occurs by changing the salt concentration in polymer solutions and the DNA fraction in polymer chains. Single-stranded DNA (ssDNA)-conjugated PNIPAM was more aggregated than double-stranded (dsDNA) when DNA charges are predominant. In contrast, dsDNA-conjugated PNIPAM was more aggregated than ssDNA when flexibility was predominant.