Seven years-round since 1999, distribution and percentage cover were investigated in Caulerpa prolifera collected from 13 stations along the coast of the Suez Canal at different depths and from different types of substrates as well as from monthly collected samples in a dense unshaded meadow at a depth of 3-7 m at Great Bitter lakes. Caulerpa prolifera start increasing their cover in Spring and continued to increase into Autumn, with maximum cover in Winter. The seasonality patterns have been correlated with changes in light, temperature, desiccation and grazing. A rapid spread and high abundance of the invaded Caulerpa prolifera were observed on sandy or muddy sea bottom in shallow protected area of the Great Bitter Lakes. Caulerpa prolifera changes the ecology of area by reducing the abundance of native marine fauna and flora.