Abstract: Saleability of tropical ornamental foliage plants and grower`s profit demand both high plant quality and productivity. The aim of this study has been to make observations during two season of the year: winter and summer, on various structural and photosynthetic parameters of five ornamental foliage plants (Aglaonema commutatum, Dieffenbachia maculata, Philodendron `Burgundy`, Philodendron peruvianum and Syngonium podophyllum) grown in a greenhouse at commercial facilities. The results from this study showed that the more a plant invests in leaf area, the higher the total carbon gain and the faster growth will be. Most foliage plants have their origins in the tropics and require relatively high night temperatures to sustain rapid growth; A significant change in growth rates would be associated to environmental seasonal influences. By other hand, estimation of leaf area through linear dimensions such as length and width of the leaf lamina and the close correlations between total leaf area and total dry weight with plant size would be an appropriate method and a useful tool for foliage ornamental productivity crop modelling.