Abstract: There are still limited experimental data of liquid diffusion coefficients in literature.Therefore, the experimental investigation and prediction model are of practical and theoretical significance.The diffusion coefficients of L-serine, L-threonine,L-arginine,in aqueous solution at 298.15 K were measured respectively by holographic interferometer.The affecting factors of molecular structure and polarity were analyzed and discussed.Finally, a modified semi-empirical model for correlating the diffusion coefficients of solid organic compounds in aqueous solutions at 298.15 K was proposed with an adjustable parameter added.The average deviation between model prediction values and experimental ones is less than 0.2%, which shows a considerably satisfactory accuracy.