We examined the effects of different photoperiods on in vitro plantlet regenerations of Paulownia plants. The results indicated that the rates of shoot induction from leaves treated with different photoperiods directly or 5 d and 10 d continuous illumination and dark pretreatments respectively were the highest under 24 h light photoperiod condition, but the time varied with leaves of different pretreatments when the induction rate was the largest. For root induction, the influences of different photoperiods on the rooting from shoots of 3 kinds of Paulownia plants were various. Much longer or shorter light illumination in the photoperiods might inhibit the rootings of the plants. The root inductions from the shoots of P. tomentosa and P. fortunei were inhibited much more than those of P. elongate.