Two perforated plates placed obliquely to a current to form a bow-shape will be effective for use in fisheries. We examined the resistance to the two perforated plates as the angle between the hinged plates and the open area ratio of the two plates were changed. We made a model by joining the two iron plates, each of which was 33cm long, 20cm wide, and 2mm thick, With hinges. The contained angle of the two plates was changed from 60 to 180 by 30 steps. we drilled holes of increasing diameter by steps and determined the ratio of the total area of the holes to the area of the undrilled plate, 'open area ratio'. The open area ratio was changed from 0% to 37.2% in eight different steps. We set up the model, changing the contained angle for each of the open area ratios in a circulating water tank and measured the resistance. We confirmed that Newton's Law is applicable to the resistance of the two perforated plates. The drag coefficient of the perforated plates for each contained angle at each open area ratio was calculated from the resistance. We showed that there is an increase and decrease of the resistance corresponding to the increasing of open area ratio.