Novel heptamethine 3H-indocyanine dyes are synthesized and embedded into a matrix of silica gel derived from tetraethoxysilicane. The photophysical properties of these near infrared dyes in various solvents and in SiO2 sol gel were investigated. The results show that the dyes containing cyclohexenylene bridge and N-(p-carboxy)benzyl groups have better photostability and longer absorption wavelength than those containing linear heptamethine bridge and/or N-(5- carboxy)pentanyl groups. The absorption maxima of these dyes are in reverse proportion to the polarity of the solvents. The microenvironment of the dyes in SiO2 sol-gel characters medium polarity (between methanol and DMF) according to the absorption maxima. Novel photochromatographic properties of these dyes are synthesized and embedded into a matrix of silica gel derived from tetraethoxysilicane. The photophysical properties of these near infrared dyes in various solders and in SiO2 sol gel were investigated. The results show that the dyes containing cyclohexenylene bridge and N - (p-carboxy) benzyl groups have better photostability and longer absorption wavelength than those containing linear heptamethine bridge and / or N- (5- carboxy) pentanyl groups. The absorption maxima of these dyes are in reverse proportion to the polarity of the solvents The microenvironment of the dyes in SiO2 sol-gel characters medium polarity (between methanol and DMF) according to the absorption maxima.