The present work was conducted to study the effect of different Lithovit (nano-CaCO₃) rates 0, 2, 4, 6, 8 and 10 g/l and irrigation intervals (1 week and 2 weeks) on enhancing growth Cycas revoluta, Thunb. seedlings, that (one year old) during two experiments of 2018 and 2019 in Antoniades Research Branch, Horticulture Research Institute, Alex., Egypt. The obtained results cleared that the two irrigation intervals had significant effects on cycas growth during the two seasons. Lithovit (nano-CaCO₃) with concentrations of (0, 2, 4, 6, 8 and 10 g/l) under the two irrigation intervals caused significant increment in leaf length (cm), number of leaves per plant, leaves dry weight (g), stem circumference, stem dry weight (g), and root dry weight. Also, Lithovit (nano-CaCO₃ enhanced the leaves contents of chlorophyll a, b and total chlorophyll, total carbohydrate, and N%. Meanwhile, there was a significant decrease in proline and electrolyte leakage (EL) % contents. The optimum concentration of nano-CaCO₃ to enhance Cycas revoluta growth under deficit water was 8 and 10 g/l in plants irrigated every week followed by 10 g/l in plants irrigated every two weeks. Finally, it can be concluded that foliar application of nano-CaCO₃ can reduce the adverse effects of drought on cycas plants