Tomato (Solanum lycopersicum) is an important economic crop. Bacterial wilt caused by Ralstonia solanacearum is a serious soil-borne disease of Solanaceae crops. Traditional controlling methods, such as cultivation of resistant varieties, crop rotation and use of chemicals, all have certain limitations. Silicon, as beneficial element to plant growth, plays an important role in enhancing plant adaptability to biotic and abiotic stresses. Proteomics is a new branch of science in post-genome era, focusing on proteomics as object to explore the full extent properties of various proteins, and further on pathogenesis, cell model and functional links of diseases at the protein level. In this study, the variety of tomato “Taiwan red cherry” which is susceptible to R. solanacearum was used. The experiment was designed as the following treatments: CK, Treatment Si (Si addition only), Treatment Rs (R. solanacearum inoculation only) and Treatment Si+Rs (Si addition followed by R. solanacearum inoculation), and the technique of iTRAQ (isobaric tags for relative and absolute quantitation) was used to analyze effects of Si addition on resistance of the tomato to R. solanacearum and soil proteome. Results showed that silicon addition significantly reduced disease index of the tomato crop by 19.4%, increased available silicon content in the soil and enhanced resistance of the tomato to R. solanacearum. ITRAQ analysis revealed that out of the 30 soil proteins identified, 29 were differentially expressed (up-regulation ≥1.2 fold and down-regulation ≤0.8 fold); isoelectric point of differentiated proteins varied between 4.1 and 10.7 and relative molecular weight in the range of 9 ~ 392 kDa; and confidence coefficient was ≥95%. Compared with CK, Treatment Si had five proteins up-regulated and nineteen down-regulated and Treatment Rs, five up-regulated and twenty-two down-regulated. Compared with Treatment Si, Treatment Si Rs had eight proteins up-regulated and fourteen down-regulated. Classification based on GO (gene ontology) function shows that of the twenty-nine differentially expressed proteins, 21.88% are involved in metabolic process, 15.63% in cellular process, 12.50% in cell communication, 3.13% in immune system process and another 3.13% in the process of response to stimulus, and classification in light of molecular function reveals that 25.64% are related to structural molecule activity, 25.64% to binding and 20.51% to catalytic activity, the three categories making up a major proportion. Classification according to protein class exposes that nucleic acid binding protein, hydrolase protein and cytoskeletal protein are the three major categories of proteins, accounting for 19.51%, 14.63% and 9.76%, respectively. To better understand effects of Treatment Si Rs and Treatment Rs on soil proteins, further analysis was done of the 22 differentially expressed proteins obtained from Treatments Si Rs/Rs. It was found compared with Treatment Rs, Treatment Si Rs had eight proteins up-regulated by as high as 1.6 folds and fourteen proteins down-regulated by 0.5 fold. All the findings indicate that Si could affect R. solanacearum by altering metabolic and cellular processes in biological process, structural molecule active protein and bindin protein in molecular function, and nucleic acid binding protein and cytoskeletal protein in protein classification. In a word, Si addition can reduce the disease index of tomato bacterial wilt significantly, thus enhancing the plant resistance to the disease. Infection of R. solanacearum down-regulates metabolic-related proteins, influences degradation of misfolded proteins, hinders signal communication and Ca² signal transduction between microorganisms and microorganisms or plants, blocks synthesis of proteins, while Si helps tomato build up its resistance to R. solanacearum infection by affecting soil microbial metabolic capability, regulating expression of resistance and metabolism related proteins, improving signal communication and transduction between microorganisms and between microorganisms and plants, adjusting synthesis of soil proteins and expression of proteins involved in immune system process and stress response and influencing signal transduction of Ca² .