To explore the influence of shading treatment on the flowering characteristics and volatile composition of Gardenia jasminoides, and to provide reference for scientific planting, maintenance and volatile composition regulation of ornamental gardenia, this study used two kinds of Gardenia jasminoides var. grandiflora and Gardenia jasminoides var. radicans as test materials, with five different shading treatmentsCK₁ (total illumination contrast, no shading), CK₂ (under the shade of Eucommia ulmoides, the shading rate was 80%), T₁ (one needle and one layer of shade net, the shading rate was 60%), T₂ (two needles and layer of shade the shading rate was 70%), and T₃ (two needles and two layers of shade, the shading rate was 90%). We researched and measured their flowering characteristics (flowering time, flowering duration, number of flowers, opening rate and morphological characteristics of flowers). We collected flowers, determined volatile composition and relative contents of two kinds of gardenia by using SPMEGCMS. The results showed that: (1) proper shading advanced the flowering time of the two gardenias, and had no obvious effect on the flowering duration. Severe shading delayed the flowering time of the two gardenia and shorten flowering duration. The bud number and normal flower number of CK₁ treatment were the highest in 5 treatments, and the open rate of CK₁ and T₁ were not significantly different, and higher than that of other treatments. (2) With the increase of shading degree, the number of buds, the number of normal flowers and the opening rate were gradually reduced, and the flower diameter/bud length decreased with the increase of shading rate; (3) There were 26 compounds in 4 major groups, including alpha.Farnesene, 3Carene, (E)hex3enyl (E)2methylbut2enoate and Linalyl acetate in G. jasminoides var. grandiflora. A total of 23 compounds were detected in G. jasminoides var. radicans, and the main compounds were 3Carene, cis3Hexenyl tiglate, Benzoic acid, methyl esterand (3E, 7E)4, 8, 12trimethyltrideca1, 3, 7, 11tetraene. (4) CK₁ treatment of the to gardenia showed the most variety of volatile components and decreased with the increase of shading rate, among which terpene substances increased first and then decreased with the increase of shading rate, and esters decreased first and then increased with the increase of shading rate. Shading treatment had great influence on the flowering characteristics and volatile composition of G. jasminoides var. grandiflora and G. jasminoides var. radicans. There was no significant difference in the effect of shading on the flowering characteristics of the two different species of gardenia, but there were significant differences in the composition and relative contents of volatile. In the arrangement of garden plants, it is suggested that ornamental gardenia should be planted in moderate shading environment, such as deciduous trees, and avoid planting in heavy light and heavy shading environment as far as possible.