The present study was intended to examine a basic scheme to determine the biochemical oxygen demand(BOD) of livestock wastewater by means of six individual dissolved oxygen (DO) sensors and its multi-measurablemeter. Maximal point of the first order time derivative of the DO difference between DO distribution of sterilizedlivestock wastewater and that of non-sterilized livestock wastewater, was considered as the oxygen uptake rate (OUR)of microorganisms in livestock wastewater, as determined to be 0.00074mg O2/ℓ.sec. The present study showed thatthere was a fair linear relationship (97.72%) between maximal OUR and BOD values of livestock wastewater, the latterbeing determined by classical Winkler azide method. It was thus concluded that the present multi-biosensor systemmight be applicable to an on-line system for measurement of BOD of livestock wastewater.