Each component of the human ear performs a specific function in hearing.The actual process of sound transduction takes place in the auditory portion of the inner ear,the fluid-filled cochlea.In the cochlea,the sensitivity and efficiency of sensory apparatus to convert mechanical energy into neural activity,largely depends on the fluidic and ionic environment.In the lateral wall of cochlea,the secretory epithelium stria vascularis plays an important role in the maintenance of fluidic and ionic homeostasis.A variety of gene mutations disturbs the cochlear homeostasis and subsequently leads to hearing impairment.The review covers several aspects of cochlear homeostasis,from cochlear fluid and the functional role of stria vascularis,cochlear K+ recycling and its molecular substrates to genetic deafness with abnormal cochlear homeostasis. Each component of the human ear performs a specific function in hearing. The actual process of sound transduction takes place in the auditory portion of the inner ear, the fluid-filled cochlea. The cochlea, the sensitivity and efficiency of sensory apparatus to convert mechanical. energy into neural activity, largely depends on the fluidic and ionic environment. In the lateral wall of cochlea, the secretory epithelium stria vascularis plays an important role in the maintenance of fluidic and ionic homeostasis. A variety of gene mutations disturbs the cochlear homeostasis and subsequent leads to hearing impairment. The review covers several aspects of cochlear homeostasis, from cochlear fluid and the functional role of stria vascularis, cochlear K + recycling and its molecular substrates to genetic deafness with abnormal cochlear homeostasis.