A study of the S/V ratio and growth equation of 49 oocytes and 120 human embryos was carried out. The S/V ratio of the internal and external limits of the zona remains unchanged during successive cleavages. The mean blastomere increases 22% its S/V ratio after each division. The mean blastomere growth equation for the 2-cell to 8-cell stages follows the expression y = 1.271 x1.021 (y = longest and x = smallest diameter), but the results obtained for the whole embryo do not coincide with those resulting from the application of the growth equation.