Trichomyia duckhousei, a new species belonging to Psychodidae Trichomyiinae, is characterized and described based on a well-preserved specimen from the lower Eocene Fushun amber of China. It shares some similarities with Trichomyia of Group B, but has some features present in the fossil record but not in Recent taxa, such as non-eccentric flagellomeres and long legs. This discovery represents the first Trichomyiinae (Psychodidae) from the Fushun amber, and adds more evidence on the very high palaeodiversity of the psychodids since at least the middle Cretaceous. An updated check list of fossil Trichomyiinae is given.