In order to develop a new type of high efficiency and stability urea suitable for rice in black soil and loess, field pot tests were conducted to investigate effects of urea combined by biostimulant laminarin and different biochemical inhibitors on rice in black soil and loess. In this study, blank (CK) and urea (N) were set as controls, and laminarin (L), N-butyl thiophosphate-triamine (NBPT), 3,4-dimethyl-pyrazolate phosphate (DMPP), and laminarin were respectively combined with two biochemical inhibitors to urea fertilizer to form five treatments, nitrogen transformation characteristics, rice growth index, yield and apparent utilization rate of nitrogen fertilizer of different high efficiency and stability urea fertilizers in black soil and loess were studied. The results showed that the addition of laminarin could inhibit soil nitrification to a certain extent, total biomass of rice in black soil and loess increased by 13.88% and 1.21%, grain yield increased by 42.18% and 25.83%, apparent utilization rate of nitrogen also increased. Laminarin and NBPT had a good synergistic effect on soil nitrification inhibition, compared with NBPT alone, total biomass in black soil and loess decreased by 6.87% and 1.30%, grain yield decreased by 8.15% and 4.11%, apparent utilization rate of nitrogen also decreased. Compared with DMPP alone, the addition of laminarin could promote the growth of rice, total biomass and grain yield increased by 0.63% and 2.64% in loess, nitrogen uptake and apparent utilization rate of nitrogen were also increased, however the total biomass and grain yield decreased by 10.52%, 1.50% in black soil, and nitrogen uptake and apparent utilization rate of nitrogen were also decreased, the combination of laminarin and DMPP had a negative effect in black soil. The addition of laminarin and DMPP is recommended for urea fertilizer application on rice in loess areas, and will improve rice yield and apparent utilization rate of nitrogen.