Abstract: In this study, the effects of different additives on the mixed ensiling fermentation characteristics of dry corn stover (DCS) and asparagus lettuce leaves (ALL) were investigated under laboratory conditions. Four different treatments were measured: control (CK), formic acid (final concentration of 3.0 mL/kg material, fresh weight, FA), Lactobacillus delbrueckii (final concentration of 1×10⁵ cfu/g material, LD) and a combination of formic acid and L. delbrueckii (FA+LD). Silages were prepared in 1.5 L laboratory-scale glass silos at ambient temperature for 50 days. Ensiling samples were removed from the sealed containers for analysis every 10 days. The results showed that for the FA treatment, the pH value, cellulose, hemicellulose and lignin content, and the ammonia nitrogen to total nitrogen ratio (AN/TN) decreased significantly during the ensiling process (P<0.05), while lactic acid (LA) content increased (P<0.05). After ensiling for 50 days, the highest LA content, the lowest pH, AN/TN and dry matter (DM) loss were found in the FA treatment, indicating good fermentation quality. The DM loss and AN/TN of the LD treatment were significantly higher than the control (P<0.05). The pH value of the LD treatment was higher than 4.2. The silage quality the LD+FA treatment was higher before 30 days than at 40 and 50 days; the AN/TN increased substantially after 40 days and was 10% higher than the recommended value for good quality silage. Based on these results, it is suggested that formic acid can be used as an ensiling additive to improve silage fermentation quality and to prolong the preservation of DCS. However, it is also necessary to consider the cost of formic acid.