The authors have been studying the relationship between physical office room environment and intellectual productivity, and have experimentally evaluated the influence of illumination and thermal environment on intellectual productivity of office workers. In these experiments, intellectual productivities of participants were measured under different physical environments where the measurement method is the most important. There are various types of intellectual works in office which are from simple information process to complex creative works and it is quite difficult to measure their productivities. In this paper, the measurement methods which the authors have been developed are introduced and the advantages and limitations are discussed.