Abstract: Hydroxyapatite (HAp) was grown on sericin coated silk fibers and non-sericin coated silk fibers using simulated body fluid (SBF) at 37 C and two concentrations of 1.0standard SBF and 1.5standard SBF. The results showed that, for both concentrations of SBF, HAp grown on sericin coated silk fibers is more than that on non-sericin coated silk fibers. This indicates that sericin on the silk fiber plays an important role on the growth of HAp on the silk fibers. Moreover, the particle size of HAp grown in 1.5SBF concentration is smaller than that in 1.0SBF concentration.