Magnetotactic bacteria (MTB) are gram-negative motile prokaryotes that produce magnetosomes and can orient and migrate along the geomagnetic lines of force. They are ubiquitous in sediments and stratified water columns, distributed predominantly in the oxic-anoxic transition zone (OATZ). MTB comprise several morphological types, including cocci, rods, vibrios, spirilla, and multicellular magnetotactic prokaryotes. Usually, cocci are the dominant morphology. Variable phylogenetic relatedness of MTB has been confirmed on the basis of 16S rRNA genes. MTB can biomineralize iron oxide and/or iron sulfide magnetosomes. In most MTB, magnetosomes are organized in chain(s). In this study, we found a certain amount of MTB in the intertidal zone of Taiping Bay, Qingdao City, where the maximum abundance reaches up to 350 ind./cm³. Transmission electron microscopy revealed that all the MTB were magnetotactic cocci, with a size of (2.23±0.69) μm×(1.84±0.47) μm and the width/length ratio of 0.87±0.10 (n=21). Fifty-four percent of the MTB contained two chains of magnetosomes, eighteen percent with one chain, fourteen percent with more than two chains and fourteen percent with cluster. All of these magnetosomes were prismatic mineral crystals. There were 7-43 (mean=18,n=21) magnetosomes in a cell and the volume of magnetosomes varied between 2.71×10⁵ nm³ and 1.63×10⁶ nm³. Assuming that all the magnetosomes were magnetite, the percentage of Fe in MTB was 0.40%-6.91% (average 2.19%) and per square kilometer of intertidal zone produced 1.92 kg magnetite every year. This suggests that MTB may play an important role in the iron biogeochemical cycle in this area. Additionally, according to the statistics for each magnetotactic bacterium, we observed that the mass of magnetosome increased with the increasing mass of MTB (r=0.637,P=0.002 < 0.05). Phylogenetic analysis based on 16S rRNA gene sequences revealed that 47 sequences of MTB belonged to 13 OTUs (XCQD1-18, 1-2, 1-19, 51, 81, 6, 2-2, 4-20, 34, 2-23, 53, 130, 1-21) and affiliated to Alphaproteobacteria. OTU XCQD1-18 containing 23 sequences had the highest dominance index (48.93%). In addition, 6, 5, 2, 2, 2 sequences belonged to OTU XCQD2-2, XCQD1-21, XCQD1-2, XCQD2-23, XCQD130, respectively. The other OTUs had only one sequence. Shannon's diversity index H' of MTB in Taiping Bay was 2.64nit, and Species Evenness J' was 0.71. Nine OTUs (XCQD 1-18, 1-2, 1-19, 81, 6, 4-20, 34, 2-23, 53) shared less than 97% 16S rRNA gene sequence similarity with the nearest known sequences, in which, five OTUs (XCQD 81, 4-20, 4, 2-23, 53) shared lower than 93%. It suggested that they represented 9 new species and 5 novel genera. Our results indicate that there were substantial potential microorganism resources in Taiping Bay. Compared to the MTB community in Huiquan Bay, a bay adjacent to Taiping Bay, here were two MTB OTUs discovered both in Taiping Bay and Huiquan Bay. Two MTB OTUs were shared. Jaccard similarity coefficient was 0.1053, indicating that although the two bays were close to each other, the MTB communities showed great differences. Comparison of the features of MTB in Taiping Bay with two French Mediterranean coasts, Six-Fours-les-Plages and Gulf of Fos, revealed that environmental factors may have a great influence on the diversity of MTB. It is assumed that community succession, seasonal variation, and environmental distinction may contribute to the low similarity between the MTB communities and features of different intertidal areas. Our results imply that further investigation on MTB in terms of their diversity is required.