Abstract: With the gold tailings of Shandong Zhaoyuan Gold Mine as the main raw materials，the effects of proportion of gypsum and C/S ratio of the system on the strength and bulk density of the autoclaved aerated concrete are investigated. And the products are characterized by XRD and SEM. The results show that gypsum can adjust the setting time of the aerated concrete，improve the early strength of the bodyware，but no significant impact on the dry strength of the products. The appropriate mixing amount of gypsum is 3% of the total mass of the tailings，cement，lime and gypsum. Tobermorite's crystals and dosage determines the strength of aerated concrete products，but is affected by the calcium-silicon ratio of the raw materials. The appropriate calcium-silicon ratio in testing is 0.7.

Key words: Gold tailings, Gypsum, C/S ratio of the System, Autoclaved aerated concrete