The article provides population morphological characteristics of the Johnius belangerii (Cuvier, 1830) based on specimens collected in the Lach Truong coastal estuary (Hoang Hoa and Hau Loc districts), Thanh Hoa province. Morphological anal-ysis shows that the Johnius belangerii has the following char-acteristics of the species: Dorsal fin with IX-X spines, the second part of the fin with I spine and 26-32 soft rays; anal fin with II spines, 5-9 soft rays; complete lateral line, up to the tip of the caudal fin, 46-65 lateral line scales; no barbels on the chin, three pairs of mental pores; gill rakers very short, 9-12 on lower limb of first-gill arch; 25 vertebrae. The article also provides data on the correlation between body part measure-ments and standard length based on correlation coefficient analysis. Most morphological measurements of body parts have a relatively close relationship with standard length, in which the smaller body parts have a less close correlation.