We present a concise review on current advances in the field of application of Nuclear Magnetic Resonance (NMR) in Structure-Activity Relationship (SAR) study of nanostructure drugs, particularly of paclitaxel-loaded nanocarriers. A short introduction of NMR to nonspecialists is also included. The review is separated into two parts, the first discusses in broader context the concepts and potentials of drug-loaded nanocarriers as the modern tumour active targeting systems and the second focuses on the paclitaxel-loaded nanocarriers, especially on conformations and tubulin-binding forms of paclitaxel. The application of nanoscience in pharmaceutical researches explodes very fast with many anti-tumour drugs recently been approved to the market. We survey only the important and latest issues in this field.