Species valuation is an essential step to effective biological management. Spaceship economy is a theory which takes Earth as a large spaceship with passengers (humankind) and limited space and resources, to optimise the allocation of natural and economic resources. From the perspective of spaceship economy, it suggests that: (1) the value of species is determined by the instrumental values provided by the species in its existing time, and spaceship economy will make species valuation become more feasible and operable; (2) species value usually increases with population to the maximum then decreases monotonically; (3) compared with allied common species, rare and endangered species usually have lower species value but higher individual value and conservation priority; (4) not all species deserve existence and conservation.