[Objectives]  To clarify the characteristics of damage to kiwifruit caused by Halyomorpha halys Stål, a stink bug that is an increasingly important pest of kiwifruit crops but which leaves no obvious signs of damage on the surface of kiwifruit. [Methods]  We used exclosures to study the type of damage inflicted by H. halys on kiwifruit at different stages of growth. [Results]  All kiwifruit examined were measured and peeled to check for damage when they were harvested. Hygrophanous spots were the main kind damage observed, most (94.39%) kiwifruit had green spots, some had both green and white spots (4.90%) and a few (0.71%) had only white spots. These spots could occur anywhere on the fruit. The incidence of H. halys damage was 100% in June and July and the intensity of damage was most severe in July (26.00 spot/fruit). There was no significant difference in the length, width, weight, firmness, sugar content or dry matter content of damaged and undamaged kiwifruit. Damaged postharvest kiwifruit typically had white spongy spots, which gradually expanded becoming flocculent, rotting tissue. Intact kiwifruit underwent no obvious change over the same period of time. [Conclusion]  H. halys can damage kiwifruit anytime between fruit set and harvest. The main growth stage (July) was the most susceptible to damage which shortens the storage period and shelf-life of harvested kiwifruit.