The poor aqueous solubility and instability of retinoic acid (RA) have limited its clinical use. Solid lipid nanoparticles (SLN) have a potential limitation which is the drug expulsion. This study was undertaken to overcome the limitation by loading RA in nanostructured lipid carriers (NLC). RA-loaded NLC was prepared by high pressure homogenization and characterized by transmission electronic microscope (TEM), particle size analyzer, zeta potential analyzer and high-performance liquid chromatography (HPLC). The results were as follows: (1) When the homogenization cycle number varied from 1 to 12, the mean particle size decreased from 120 nm to 10 nm, while P.I. (polydispersity index) increased from 0.26 to 0.69. (2) The spherical shape observed by TEM indicated a better drug loading capacity over SLN. (3) The concentration of all-trans retinoic acid (ATRA) in NLC reached 56.26 mg/mL compared to 20 mg/mL dissolved in silicone oil and the photostability of ATRA was improved so that the effective concentration of RA could keep for a longer time. (4) As far as the stability of NLC was concerned, its z potential value was (-30.90.6) mV and it remained stable after 120 min centrifugation (4℃, 10000 r/min) or 6 month light-proof storage. Furthermore, freezing-drying (-40℃, 0.01 Pa), which increased its mean particle size and reduced its P.I., could also be used to increase the NLC stability. Taken together, RA-loaded NLC is a promising drug form for clinical use.