Abstract: Five organic dyes of D-x series were synthesized which contained triphenylamine (TPA) moieties as electron donors and cyanoacrylic acid moieties as electron acceptors, alkyl thiophene (alkyl chain were H、CH3、C4H9、C6H13、C8H17 respectively )as π-conjugated linker. The effects of both the alkyl chains and the length of the alkyl chains on the photo-physical, electrochemical and photovoltaic properties of the dyes were studied. The results indicated that D-2~D-5 dyes with alkyl chains the UV-Vis absorption spectra were occurred blue shift; With prolonging alkyl chains, the short-circuit photocurrent density (Jsc) decreased gradually, while open-circuit photovoltage(Voc) and fill factor (FF) were improved. The results of photovoltaic performance indicated that PCE of D-2 with methyl substituent (5.64%) is slightly higher than that of other dyes.