This study was carried out to consider the reason the diamondback moth, Plutella xylostella(L.) frequently did not lay eggs directly on objects suitable for feeding for newly hatched larvae. When leaves of cabbege or broccoli were placed in glass tubes as ovipositional objects, only 10 to 20% of eggs were deposited on leaves; the remainder were found on the tubes' inside walls. On the other hand, when a piece of leaf from which wax bloom was removed by synthetic detergent was placed in a tube, 75% of the eggs were deposited on it.The eggs were tightly adhered to the surface of the objects and showed a more flattened shape when they were deposited on the treated cabbage leaf. These results suggested that the cabbage leaves were basically attractive to the ovipositing females, but that wax bloom on leaf surfaces considerably suppressed oviposition.