The purpose of this study is to measure the fluorescence properties of Indocyaninegreen (ICG) which is a fluorescence dye to be used as a fluorescence probe for the use of fluorescence imaging in biomedical applications. The fluorescence molecular imaging is expected to solve the issues in preclinical studies which require a lot of time, labors and sacrificed animals. Information of living body can be obtained by measuring the fluorescent properties of the probe in biological media. The absorption and emission spectra and the lifetime of ICG in non-scattering and scattering media were measured in this study. ICG was dissolved in water, in plasma, in Intralipid, and in a mixture of plasma and Intralipid to simulate the environment in living tissues. The absorption and emission spectra were measured using a fluorescence spectrophotometer. The fluorescence lifetimes were measured using a time-resolved measurement method. Results suggest that the fluorescent properties are affected by the reaction between ICG and biological tissues.