Three kinds of plant growth regulators, gibberellinA 4/7 (GA 4/7 ), 6-benzylaminopurine (BA), and chlormequat chloride (CCC), were evaluated for their ability to promote strobilus and cone production in a Chinese pine (Pinus tabuliformis Carr.) clonal seed orchard. Treatments (0, 250, 500, or 1000 mg L -1 ) were applied during three periods (June- July, July-August and August-September) in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed with GA 4/7 (500 mg L -1 ) from June to September had significantly more female strobili and immature cones than controls and other treatments (p≤0.0001). The best time to apply GA 4/7 was in June. BA at 500 mg L -1 significantly increased female flower and immature cone production, compared to other treatments and controls (p≤0.0001), while promotion of male strobili was unchanged. Chlormequat chloride at 1000 mg L -1 significantly increased the number of male strobili, compared to the other treatments (p≤0.0001). Spraying CCC at500 mg L -1 significantly increased the number of female strobili, compared to controls (p<0.05), but it had no effect on immature cone production (p>0.05). These results are important for improving seed production and seed orchard management of Chinese pine. Three kinds of plant growth regulators, gibberellin A 4/7 (GA 4/7), 6-benzylaminopurine (BA), and chlormequat chloride (CCC), were evaluated for their ability to promote strobilus and cone production in a Chinese pine (Pinus tabuliformis Carr.) Clonal seed orchard. Treatments (0, 250, 500, or 1000 mg L -1) were applied during three periods (June- July, July- August and August-September) in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed with GA 4/7 (500 mg L -1) from June to September had significantly more female strobili and immature cones than controls and other treatments (p ≦ 0.0001) . The best time to apply GA 4/7 was in June. BA at 500 mg L -1 significantly increased female flower and immature cone production, compared to other treatments and controls (p ≦ 0.0001), while promotion of male strobili was unchanged. Chlormequat chloride at 1000 mg L -1 significantly increased the number of male strobili, compare Spraying CCC at 500 mg L -1 significantly increased the number of female strobili, compared to controls (p <0.05), but it had no effect on immature cone production (p> 0.05). These results are important for improving seed production and seed orchard management of Chinese pine.