A family of 3-ferrocenylazobenzene-attached dendrimers. 9mer, 27mer, and 81 mer, which is the first series of redox-active photochromic dendrimers exhibit photochromisin responding to three different light Sources, i.e.. 365, 436, and 546nm lights. Decreases in the size of the dendrimers induced by trans-to-cis photoisomerization appeared and became more significant with increases in the size of the dendrimers up to Miller. Electrochemical treatment of the Miner provided a photo-sensitive and redox-active dendrimer film-coated electrode.