New techniques applied for studying body protein turnover in domestic animals and humans have been reviewed briefly in terms of mode of tracer administration and measurement of both protein synthesis and degradation. Current interests in analytical technology concerning protein turnover are centred around the use of stable isotopes and computer simulation. The use of stable isotopes will greatly be expanded for the study of protein turnover in tissues and whole-body of animals for safety reasons. Attention should be made on the use of computer simulation which may be of great importance in saving time and money necessary for setting up basic conditions of turnover studies. As an example of new technique application, also described is a whole-embryo culture method which is useful for quickly searching physiologically active substance to increase whole-body protein synthesis. In addition, by the use of indirect calorimetry in conjunction with protein turnover measurements, a linking of protein turnover to energetic expenditure is discussed.