Population structure of the caltrop snail Murex tribulus at Bardawil lagoon, North Sinai, Egypt had been studied to evaluate their community structure in their habita. A total of 2400 individuals of Murex tribulus were randomly collected from landing site during the fishing season in Bardawil lagoon from June 2019 to February 2020 and from June 2020 to February 2021. The relationships between total length (TL) and total width (TW) of males (with total width range from 15 to 29.6 mm) and females (with total width range from 15.8 to 35.6 mm( and combined sexes (with total width range from 15 to 35.6mm) were determined to quantify shell size. Relative growth showed negative allometric growth (where b>1) was observed in males and females of M. tribulus in terms of the following body parts: top length (PL), bottom length (BL), aperture length (AL) and aperture width (AP) for males, females and combined sexes. The relationships between total length (TL) and (total weight TWt and flesh weight FWt) of M. tribulus illustrated a positive growth where b>1 for both sexes and combined sexes. However, the sex ratio was more or less constant throughout the season, except in August, January and February where females exceeds males. Generally, the total ratio for males and females was 1: 0.8.