The present work investigates the relationship between the growth kinetics and the crystal structure of N-methylurea (NMU) crystals. Anisotropy of the step kinetic coefficient, step free energy, and normal growth rate of NMU crystals may be explained on the basis of a model which links the above quantities with the energy of kink formation in the growth steps. The proportionality condition between the solid-solid and solid-liquid bonds has been applied, and the coefficient of this interaction was obtained experimentally. The anisotropy of the crystal habit observed in these experiments is much greater than that predicted by the attachment energy model. We suggest that the method may be generally used to quantify the crystal growth anisotropy of molecular crystals.