Marine zeolites were not really studied until 1950. Among them, analcimes are considered as third in order of importance after clinoptilolites and phillipsites; they are also the least known. This is why this study was chosen. The aim is to determine the physico-chemical (temperature, pressure, nature of interstitial solutions...) and sedimentologic parameters which govern the crystallization of analcimes, and influence their chemical composition. Starting with the principle that certain mineral species which coexist with analcimes form with them in paragenesis, and considering their respective domains of stability, an attempt is made for the definition of the conditions of formation of this zeolite in marine environments.