The peculiar skin condition to which Mibelli gave the name porokeratosis appears to be more common in the Orient than in the West. The earliest series of cases was reported in 1893 from Majocchi's clinic in Italy by Mibelli1and Respighi,2but Neumann3probably saw a case in 1875, describing it as "a previously unknown skin condition (dermatitis circumscripta herpetiformis)." Until 1905, almost one half of the known cases had occurred in Italy (Mibelli4); other cases having been reported from America5and Germany.6Since then cases have more frequently been reported from France,7America,8Germany9and England,10but a proportionally larger number has come from Japan and Korea.11So far cases have not been reported from China. This paper covers a series of six cases in Chinese patients seen during the course of two years in Peking. REPORT OF