The total reaction cross sections (TRCSs) of 29 S+28 Si have been measured at intermediate energies. An obvious enhancement in TRCS of 29S is observed as compared with its neighbouring nuclei. The TRCSs of 29S+28Si are calculated with the modified Glauber theory in the optical limit and few-body approaches. The different factor d as a possible measure of halo appearance is deduced from the experimental and theoretical data. It is well accepted that 27p is a proton halo nucleus. Although not as anomalous as 27p, the different factor d of 29S is obviously larger than that of its neighbouring isotones of N = 13. This result indicates that a moderate proton halo may exist in 29S nucleus. We calculate the total reaction cross sections for 29S with the modified Glauber theory as a function of incident energy and compare the results with those for 27 Si which is a core nucleus of 29S.The measured TRCSs of 27 Si+28 Si can be described to be satisfactory by the modified Glauber theory of the optical limit approach. Although a diffused nuclear density distribution is used, the theories still inadequately predict the experimental TRCSs of 29 S+28Si, which further indicates the possibility of proton halo in 29S.