In this research, nanocomposite scaffolds of chitosan/PLLA/nano calcium phosphate (average crystallite size of 16.5 nm) have been prepared via the freeze-casting method and then characterized. The effects of nano powder contents on the structure of scaffolds were investigated to provide an appropriate nanocomposite for bone tissue engineering applications. The results showed that the scaffolds had high porosity (up to 98%) with open pores of 80-380 mu m in diameter. It was also shown that the porosity increased with decreasing nano powder content. Furthermore, the bioactive nano calcium phosphate was homogenously distributed within the polymeric matrix of scaffolds, which contained up to 40% of nano powder. Microstructure studies showed that the pores were distributed very well throughout the structures. This macropores structure with interconnected pores provides the properties of scaffolds required for bone tissue engineering applications.