We used stomach content analysis to evaluate the feeding habits of the dominant fish species in Laizhou Bay. The species were classified into one of five feeding habits, including zooplanktivores, benthivores, piscivores, omnivores, and generalist predators. , and is omnivorous; , Chaeturichthys stigmatias are benthivorous; Synechogobius hasta and are generalist predators. Of the species that are harvested commercially, fish were the dominant taxa in the food web from 1959 to 1993. However, the biomass of invertebrates, including , has gradually increased and constituted 42.8% of the total biomass in 2008 and 72.1% in 2011. Thus, invertebrates are now the dominant taxa among harvested species. The food web in 1959 included benthivores, piscivores, and generalist predators, among which piscivores accounted for 78.7% of the biomass. More recently, piscivores have been absent from the food web in Laizhou Bay, except in 2008. Zooplanktivores were the dominant species in 1982 and 1993, accounting for 71.1% and 72.2% of the biomass, respectively. From 1998 to 2008, the biomass of zooplanktivores declined and the biomass of benthivores increased dramatically. In 2011, the food web in Laizhou Bay included only benthivores and generalist predators, among which benthivores accounted for 82.6% of the biomass. Using cluster analysis and a simplified version of the food web from 1959 to 2011, we showed that the food web in Laizhou Bay has experienced five stages of evolution, changing from a piscivore-dominated system to a zooplanktivore-dominated system, to a zooplanktivore and benthivore system (with a higher proportion of zooplanktivores), to a benthivore and zooplanktivore system (with a higher proportion of benthivores) to a benthivore-dominated system. The species at low and medium trophic levels have replaced the species at higher trophic levels and have become the top predators in the Laizhou Bay ecosystem. The food chain is now considerably shorter and energy transfer occurs primarily through the detritus food chain. The mean trophic level declined from 4.4 to 3.4 between 1959 and 2011, which is more rapid than in the Bohai Sea. Variation in dominant species composition, individual miniaturization, and intraspecific changes in feeding are the primary factors explaining the decline in the trophic level in Laizhou Bay.