Chinese cabbage (Brassica rapa L.) is a group of plants from the Brassica genus that are used as leaves for food (vegetables), both fresh and processed. White mustard is included in horticultural crops that have high economic value. Some species of the genus Brassica have similarities with each other. Mustard has nutrients such as calcium, folic acid, and magnesium as well as vitamins A, B, C, E, and K. Farmers in Serang village have problems not only in the field of production costs, but also have experienced crop failure due to diseases caused by microorganisms, so the need for control to increase the productivity of chicory plants. This study aims to determine the types of diseases caused by fungi on chicory plants, find out the fungi that cause disease in chicory plants and determine the percentage of emergence of fungi that cause disease in chicory plants in Serang village, Karangreja District, Purbalingga Regency. The research used a survey method with purposive random sampling at two different locations in Desa Serang, Kecamatan Karangreja, Kabupaten Purbalingga. Identification of disease is done by looked at the signs and symptoms macroscopically, while the fungi that cause disease are observed for their micromorphological and macromorphological characters. Identification, followed by Postulate Koch. The results of research in Serang Village, Karangreja Subdistrict, Purbalingga Regency, found that the types of diseases in chicory are wilted leaves and leaf spot. The fungus that causes leaf wilt is caused by the fungus Fusarium sp. and leaf spot disease caused by Botryodiplodia sp. And the most common diseases that occur in chicory plants are leaf wilt disease by Fusarium sp with a frequency of appearance 199 times and the percentage of disease is 50.95% and leaf spot disease by Botryodiplodia sp with a frequency of appearance 77 times and the percentage of disease is 17.