Abstract: From 1987 to 1989, applied experiments with seedlings and rooted cuttings have been carried out both in greenhouse and nursery. It was shown that 5 ppm NL-1 or NL-32 treatment was optimum for P. elongata and P. tomentosa seedlings in solution culture experiments partly by steady state nutrition, average biomass increments of seedlings were up about 40% in comparison with control (no rare-earth). The growth of seedlings was inhibited at 50 ppm without ajusting pH value of culture solution (about 4), whereas biomass increased by 7%~30 % for P. elongata seedlings after ajusting pH near 6 with CaCO3. Spraying the leaves of nursery stocks in Paulownia spp. with NL-1 complex rare-earth solution at 50 ppm for the early two times and 75 ppm once later (pH5.0~5.5), the percentage of first class nursery stocks raised by a big margin in comparison with control, direct extra income per ha will be 3 000 yuan per year.