Abstract: This paper discusses the HY-1A rocket, an innovation in catalyst seeding technology. We compare the HY-1A rocket with traditional rockets which are used for rain enhancement or hail suppression. With the HY-1A rocket, the linear seeding mode of the catalyst is replaced by a spatial seeding mode. The diffusion of the catalyst which is released using the linear seeding mode and spatial seeding mode were approximated as linear source diffusion and instantaneous point source diffusion, from the HY-1A and traditional rockets, respectively. Based on the analytical solution formula of the two diffusion modes, the radius of effective region by catalyst diffusion and the volume of the effective region resulting from the two kinds of seeding modes were estimated.When comparing a given threshold of concentration, the volume of the effective region as a result of the catalyst diffusion by spatial seeding was 3.6-7.2 times greater, and the effective region from spatial seeding was larger for longer, than from linear seeding. A rocket with linear seeding mode or spatial seeding mode could apply different seeding objects, and subsequently we could improve and optimize rocket seeding techniques.