Osteoporosis is a degenerative bone disease characterised by progressive loss of bone mass and deterioration of bone's mechanical properties. Healing bone defects is a challenge in clinical practice, which requires the development of innovative biomaterials. The aim of this work is to develop injectable bioactive composite hydrogels for osteoporotic bone regeneration based on hydroxyapatite nanoparticles (nHAp) and hyaluronic acid (HA). In situ forming HA/nHAp composite hydrogels with HA to nHAp mass ratio of 70:30 wt%, 60:40 wt%, 50:50 wt%, 40:60 wt%, 30:70 wt% were fabricated by covalently cross-linked HA (molar ratio of EDC to NHS was 1:1) and chemically precipitated nHAp. The effect of nHAp phase on the swelling degree, gel fraction, enzymatic and bio-degradation, injectability, viscoelastic properties, morphology, and molecular structure of the hydrogels was investigated. It was observed that the addition of the nHAp phase to the hydrogel synthesis medium increased the gel fraction from 47 to 75 %, reduced the mass loss after biodegradation from 41 to 23 %, increased the enzymatic degradation time by 5 times, and reduced the swelling degree by 4 times compared to the HA hydrogel. The higher the mass fraction of nHAp in the composite hydrogel, the higher the injection force. All samples showed a good ability to recover viscosity after injection. Future studies will focus on drug release studies and in vitro biocompatibility tests of the composite hydrogels.