A carrier anaerobic baffled reactor (CA BR), containing hollow-sphere bamboo carriers, was used to examine the effects of organic and temperature shock loads for a constant hydraulic retention time. The relationships among the macroscopic observables (pH, COD and SS), catabolic intermediates (VFA) and microcosm alternation (TTC-DHA) were studied. A slight fluctuation in pH was observed, ranging from 6.5 to 7.5 throughout the experiments. The CABR had a COD removal efficiency of 91% with an effluent suspended solids (SS) of 15 mg L-1 at 28 degrees C and a feed strength of 600 mg L-1 chemical oxygen demand (COD). The reactor could run steadily without souring due to the volatile fatty acids (VFA) production(<150 mg L-1) and low VFA/alkalinity ratio (<0.23), although the effluent VFA concentration increased with decreasing operational temperature. For a substrate low in nutrient, the microorganisms converted the limited substrate into acetate to supply the essential nicotinamide adenine dinucleotide for cellular synthesis. The tetrazolium chloride-dehydrogenase activity (TTC-DHA) of the attached biomass was higher than that of flock biomass at low feed concentration, whereas the result was the opposite at high feed concentration. Microorganisms with lower activity but higher shock resistance were dominant in the first chamber. Therefore, the CA B R had high shock resistance and adaptability irrespective of temperature and feed strength.