Novel heteroleptic ruthenium(II) complex was designed and investigated theoretically, [Ru(F(2)HexOppy)(NCS)(tctpy)] with ppy derivative for heteroleptic donor to increase molar absorptivity compared to N749 (tctpy = 4,4 ',4('')-tricarboxy-2,2 ':6 ',2('')-terpyridine, F2HexOppy = 2-(2',4'-difluorophenyl)-4-oxyhexylpyridine). Generally, absorption spectrum of dyes with ppy derivative was red-shifted and broadened compared to N749, especially, in the region above 650nm. This is attributed to the heteroleptic donor system of these dyes. According to the molecular orbital analysis, we observed the LUMO mainly localized on tctpy (4,4 ',4('')-tricarboxy-2-2 ':6 '.2('')-terpyridine) moiety in N749. In case of HOMOs were localized on NCS moiety. However, HOMO of [Ru(F(2)HexOppy)(NCS)(tctpy)] were delocalized over Ru-F(2)HexOppy-NCS and HOMO-1 were delocalized on Ru-NCS moiety, respectively. These results, new type Ru(II) complex would show higher photovoltaic efficiency compared to N749 as dye sensitizers.