The aims of this work were to evaluate the content of carbon in dissolved organic matter (DOM) and particulate organic matter (POM), identify the organic carbon in the suspended matter and characterise the optical properties of DOM in the lagoon lakes Blagodaty and Golubichnoe of the Sikhote-Alin Nature Reserve. For comparison, a small lake of tectonic origin Vaskovskoe, located in the Dalnegorsk urban district of Primorsky Krai, was included in the study.