Cold damaged mandarins caused by low temprature and snow at harvest season were very severe at Jeju in 1975, and the storage diseases were also unusually serious in connection with water rot. The control measures for these problems in citrus culture are not developed yet in Korea. For the control of fruit rot diseases in the storage, fungicide applications with the use of various containers are tested. Thiofernate (Topsin WP $70\%$, X 1, 200) treatments with wooden boxes and PVC containers were very effective, but for the practical and satisfactory solutions on the storage diseases control of citrus, Benlate and Sumicidin applications are also considered.