Allometry, population dynamics, shell growth and age of the bivalve Venerupis (Ruditapes) decussatus were reported during the period from September 2007 to August 2008. The specimens (≈ 100 specimen) were collected monthly- at the time of full moon as much as possible- from the northern Mediterranean Sea coast of Port Said (31° 15̀ N, 32° 30̀ E), Egypt. The different shell parameters i.e. length , height, width, weight of the shell in addition to total weight of the specimen and weight of soft parts were measured. The results revealed that the length- height, total weight- weight of the shell is linear relationships. Meanwhile, length- total weight is an exponential relationship. The relevant equations are reported for the whole period of study. Size- frequency distributions (SFD) indicated that there are two periods of recruitment in the population of Venerupis decussatus; the first during the period from February to April and the second during June to August. Shell growth was investigated and the age of each individual was ranged from 1 to 15 years old. Shell growth is greatly influenced by the decrease of temperature.