Abstract: The effects of different structures of rice-Azolla combination system on rice and Azolla productions are studied within a 5-years experimental period. The results show that Azolla production on rice fields is significantly increased with increasing Azolla inoculation.Though the Azolla production is increased on the fields with alternating wide and narrow row rice plantings, the rice yield is decreased by 3～7%. The structure with an equal row rice planting of 30cm and an Azolla inoculation rate of 325kg·hm^-2 (wet weight) is recommended for developing rice- Azolla combination system in northern China.

Key words: Single-croppijng rice, Rice field ecosystem, Rice-Azolla combination, antioxidant capacity, introduction and acclimatization, Rhodiola kirilowii, volatile constituent, bioactive compound