Abstract : Fluorescence emission and excitation spectroscopy were used to detected the energy transfer between pigments in outer antenna (LHC II) subcomplexes, monomer, trimer and aggregate. The spectra showed that energy transfer efficiencies between pigments are high in trimer, lower in monomer. In the case of excitation 520 nm, the energy transfer efficiency from carotenoid molecule to chlorophyll a is about 64% in trimer, and 56 % in monomer. In the case of excitation 650 nm, the energy transfer efficiency from chlorophyll b to chlorophyll a is about 89% in trimer, and 78% in monomer. The energy transfer in aggregate is complex. The analysis about spectra showed that aggregate contain two kinds of chlorophyll b. Their absorption peaks are 480 nm and 468 nm, respectively. From chlorophyll b molecule absorbing at 480 nm to chlorophyll a molecule emitting at 685 nm, the energy transfer efficiency is less than 75%.