The songs of Japanese marsh warblers (Megalurus pryeri) were recorded during May to July in 2009 at Shuangtaihekou Nature Reserve, Liaoning, China. Based on song characteristics, songs were divided into three types: courtship songs, alarm calls or contact calls. We analyzed and measured four parameters from 543 verses recorded from 20 males. The parameters were: duration of verse, number of syllables, duration of syllable, and interval of syllable. Verses of courtship song are formed of two verses, the first part's rhythm is more and more quick with time; the main body part is formed with complex syllables. Alarm calls and contact calls are simple, and formed with simple and repeat syllables. All songs contained 38 syllable types (six syllable types of the first part included). Acoustic features of the courtship song were statistically different, as was the calls of each individual.