[Objective] To research the suitable planting density of hybrid cotton under wheat-cotton intercropping in south of Hebei Province.[Method]With insect-resistant hybrid cotton Hanza 9 as the research material,field experiments were conducted in Quzhou Demonstration Site to study the effects of plant density( 3. 75 × 104,4. 50 × 104,5. 25 × 104,6. 00 × 104,6. 75 × 104 plants / hm~2) on agronomic characters and yield of cotton in wheat-cotton intercropping system in south Hebei province. [Result]Planting densi...