Investigations were made on spatial and temporal variation, population structure, growth, recruitment and mortality in the intertidal flats of Kunsan (Korea, Yellow Sea) of an inarticulate brachiopod Lingula unguis. Statistical analysis indicates significant spatial differences and a significant relationship between density and ratio of sands to silts, suggesting that the distribution and density of this species were related to particle size. The population consisted of three year-classes, with a similar size composition each year, of which the second year-class was a major component. From estimation of parameters of growth monthly length–frequency was analysed by ELEFAN. Parameters of growth were estimated, using the modified von Bertalanffy growth function (VBGF) model incorporating seasonal variation in growth. The growth parameters are: L∞=44.00 mm SL, K=0.88 y−1, C=0.90, WP=0.48. The recruitment pattern shows two major recruitments per year. The maximum life span is estimated as 3.45 y. Total mortality (Z) by length-converted catch curve was estimated at 3.65 y−1. The population mainly occurred in fine sands and exhibited patchy distribution.