Our study designed to examine associations between factors of indoor air pollutants and reporting sick building syndromes (SBS) from employees of large air-conditioned office buildings. Three hundred and twelve participants from eight office buildings have returned their questionnaires. By using principle component analysis, night indoor variables with "airborne" nature were then found clustered into 4 major components according to the loadings of these variables, explaining about 88% of the variance for individual variables of interest. Microbial contamination seemed to be associated with increasing risk of reporting irritating symptoms, especially for dry, itching skin, and fatigued eyes (OR=7.87 and 2.88), and increasing risk of reporting neurotoxic symptoms, such as unusual fatigue (OR= 3.90). Our findings suggest the immediate regulation of microbial contamination in indoor building environments, and further research is needed to explore the associations between high levels of microbial exposure and corresponding health implications.