An extremely halophilic archaeon, strain Fa-1(T), was isolated from a marine solar saltern in Fujian, China. Strain Fa-1(T) required Mg2+ and at least 2.0 M NaCl for growth. It was able to grow at pH 6.5-9.0 (optimally at pH 7.0-7.5) and at 20-55 degrees C (optimally at 37-42 degrees C). The major polar lipids of strain Fa-1(T) were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a sulfated diglycosyl diether. On the basis of a 16S rRNA gene sequence analysis, strain Fa-1(T) was closely related to nine species of the genus Halorubrum, showing sequence similarities of 97.4-98.4 %. The G+C content of the DNA of strain Fa-1(T) is 64.9 mol% (Tm). DNA-DNA hybridization values between strain Fa-1(T) and the most closely related members of the genus Halorubrum were below 51 %. On the basis of the data from this study, strain Fa-1(T) represents a novel species of the genus Halorubrum, for which the name Halorubrum litoreum sp. nov. is proposed. The type strain is Fa-1(T) (=CGMCC 1.5336(T) =JCM 13561(T)).