Characteristics of the individual ecological field gradient of the endangered plant Alsophila spinulosa was studied by constructing the individual ecological field gradient model. With the increment of the distances to field source plants, the individual ecological field gradients of Alsophila spinulosa increased gradually at first to the maximal values, then decreased gradually and converged at zero at last. The varying form fitted Rayleigh distribution. Variances were found among the varying amplitudes of the individual ecological field gradients of Alsophila spinulosa in different sites. The maximal gradient values and effect distances of the maximal gradients also varied. With the increment of effect distances, the convergent velocities of field gradients were different.
