IN THE PRESENT study we aimed to evaluate the effect of using magnetic water in irrigation of the wide spread medicinal and economic plant;Calotropis procera, throughout the cultivation of the target species in open protected area under the prevailing external climatic conditions of Taif, KSA. Periodic readings of the growth parameters in the seedling, juvenile, mature and flowering growth stages was carried out using magnetic and nonmagnetic water. Measurements of the chemical coposition (proteins, lipids, carbohydrates, fiber and ash), phytohormones (GA3 and IAA), plant pigments (Chlorophyll a, and b, xanthophylls and carotene), and some enzyme activities of the target species (amylase, peroxidase and protease) were carried out by the end of the greenhouse experiment. The effect of magnetic water treatment to C. procera demonstrated significant stimulating effects on the growth criteria of treated plants as compared to control plants. The root-shoot (R:S) ratio for all treated C. procera plants either by magnetic or nonmagnetic water, in almost all growth stages except the seedling stage, was almost lower than one. Considering C. procera plants irrigated with either magnetic or nonmagnetic water during the juvenile growth stage, the allocation of leaves was the highest among the other plant organs recording maximum values amounting to 51.41, 62.74, 63.64 and 33.12% for control, T1 (treatment 1), T2 (treatment 2) and T3 (treatment3) plant samples; respectively. Comparing values of water contents of different plants showed general increase in the following order: leaves> flowers> stem> root. The number of leaves in the flowering growth stage recorded 14.66, 22.34, 28.37 and 29.98 in C. procera plants referred control, T1, T2 and T3; respectively. The relative growth rates (RGRs) of C. procera control plants is generally higher than that of C. procera irrigated plants with magnetic water especially in the case of the first and third growth stages. In most cases, magnetic water increased all element and metal contents of C. procera leaves as compared to those irrigated by nonmagnetic water, except for iron and calcium. The magnetic water stimulated the production of phytohormones and photosynthetic pigments as compared to the control. In addition, the current study proved that magnetic water increased the enzyme activity of amylase and decreased that of protease and Peroxidase.