Abstract: Maize lodging and increasing yield are considered to be the two inter-restraining factors. Crop chemical control can reasonably coordinate the relationship between them. Xianyu 335 was used to investigate the effect of a novel plant growth regulator N,N-diethyl-2-(hexanoyloxy) ethan-1-aminium (2-chloroethyl) phosphonate (called DHEAP) on plant morphology and yield in spring maize. The results showed that, application of DHEAP solution through spraying it on leaves at early jointing stage, 1) plant height was decreased, ear height and basal internodes length were significantly shortened, internode diameter was increased, and there were obvious dose effect relationships; 2) the strength of breaking-resistant of 2nd and 3rd internodes was improved so that increasing the ability of resistant lodging and; 3) the effects of DHEAP on kernels per ear and 1 000-kernel weight were different in two years or three does of DHEAP. The yield was increased by 3%-8%. DHEAP application decreased the IAA and GAs content and the value of GAs/ABA, and increased ABA content in the 3rd internode. Maybe it is the physiological mechanism for DHEAP regulating maize plant morphology.