In the present study, the atomization characteristics of a twin-fluid nozzle, which will be the component of a fuel reformer in 1 ㎾ SOFC system, were preliminarily investigated. Diesel and air were used as the test fluids. With two air cap sizes(1.6 and 4.5 ㎜) of the nozzle, the atomization of diesel fuel was visualized, and the approximate spray angle, the diesel flow rate and the average droplet size(SMD) of diesel were examined with the air flow rate and the difference of height(between nozzle and diesel level in diesel container). As the air flow rate and the difference of height were increased, the diesel flow rate sprayed from the nozzle was increased. For the air cap sizes of 1.6 and 4.5 ㎜, the average droplet sizes ranged from 20 to 80㎛, and from 50 to 250㎛, respectively. From this study, it was confirmed that the twin-fluid nozzle could be applied in the 1 ㎾ fuel reformer.