The purpose of this research was to study productivity rate in concrete plastering of interior brick wall by studying 2 construction projects in Bangkok. The researcher divided the methods of labor productivity into two categories: (1) direct labor production technique and (2) field rating technique. The direct labor productivity technique of project A is about 1.38 m2/person/hr. and project B is about 1.19 m2/person/hr. by field rating technique project A had 77.75 % of workers in work status project B had 73.75% of workers in work status. The error rate was 4.08 % and 4.31 % respectively at the 95% confidence level. Project A has higher productivity rate than project B because project manager A chooses ready-mixed plaster for plastering. Project B selects cement mix (silica cement) mixed with fine sand cement mixer and water which take longer to prepare than Project A resulted cost of materials increase for 28.21 %.Meanwhile the working time for wall plastering could take longer for 13.77 %. It can be concluded that the selection of material for work is another factor affecting labor productivity