Gene therapy is a perspective and rapidly developing field of modern medicine, which is expected to improve state of or even cure patients that are not curable by classical methods of therapy. The logics of development of gene therapy in the near future will require the use of systems in which expression of therapeutic gene can be regulated. This review critically evaluates current regulated systems of gene therapy that can be divided into two major classes. The first class is formed by systems in which induction of therapeutic gene expression is effected by an external inducer introduced into an organism. The second class includes systems based on autoregulation principle that function without an external inducer. The review evaluates the most important systems of gene expression regulation belonging to the first class, namely systems based on tetracycline regulation, dimerization induced by rapamycin derivatives, regulation by steroid hormones, regulatory RNAs and physical principles. The most important systems of the second class that are regulated by oxygen or glucose levels are also discussed.