[Objectives]  To investigate the effects of different levels of fertilizer reduction on the occurrence of three species of wheat aphids (Schizaphis graminum, Sitobion miscanthi and Rhopalosiphum padi) and two species of wheat mites (Penthaleus major and Petrobia latens), and on wheat yield, in wheat fields in Shandong. [Methods]  The population dynamics of wheat aphids and mites, which are the main crop pests in wheat fields, were studied under standard (600 kg/hm²), 10% reduced (540 kg/hm²), 20% reduced (480 kg/hm²), 37.5% reduced (375 kg/hm²) and 50% reduced (300 kg/hm²), applications of fertilizer. Yield indices (including biomass per ear, ears per meter of wheat row, seed weight per 10 ears, weight of 1 000 seeds and yield per 667 m²) under the above fertilizer levels were also investigated. [Results]  The occurrence of wheat aphids and mites were reduced to different degrees by the different levels of fertilizer application. The occurrence of S. graminum and S. miscanthi were strongly, and negatively, correlated with the level of fertilizer reduction. However, the level of fertilizer application had no significant effect on the seed weight per 10 ears or per 1 000 seeds. Reducing the amount of fertilizer by 50% significantly decreased the biomass per ear, ears per meter of wheat row and yield per 667 m². However, a regression model indicates that wheat yield is not affected when the amount of fertilizer is reduced by < 23.16%. [Conclusion]  Moderate reduction in the amount of fertilizer applied to wheat fields reduces the abundance of the main wheat pests without greatly affecting wheat yield.