This PPG entitled “A Study on Etiological Factors of Schizophrenia” (SEFOS) focuses on searching for the separate etiological factors under the understanding that schizophrenia is a complex disorder. Multifactorial model has been most often proposed as the etiological model. Up to now, fragmented knowledge of etiological factors, including genetic factor and environmental insults were reported in literature, and a two-strike hypothesis has been proposed. This PPG of SEFOS formulates a dynamic etiological hypothesis of schizophrenia. Specific, however heterogeneous, genes are hypothesized to be located in chromosome 1q, 6P, 8P, 15q, and 22q; specific environmental insults or stress are hypothesized to be acting in the vulnerable brain a long different stages of biological and/or psychological development. The interaction of specific genes and specific environment insults/stress along different stages of development will result in specific neurobiological abnormalities as shown in neuropsychological, neurophysiological and neurochemical/neuroimaging abnormalities. For this hypothesis testing, this PPG of SEFOS designs 3 projects of: (1) A Study on Neurobiology of Schizophrenia; (2) A Study on Environmental insults/stress of schizophrenia; and (3) Molecular Genetics Study of Schizophrenia. Project No.1 aims at finding different levels of neurobiological and anatomical abnormalities; Project No.2 aims at finding different levels of environmental insults/ stress; Project No.3 aims at locating vulnerability genes in different chromosome regions. A core unit for administrative integration, for case/family recruitment and statistical analysis is also designed. The dynamic etiological complex will be explored under multivariate statistical analysis. This PPG of SEFOS adopts multidisciplinary approach including clinical psychiatrists, psychopathologists, neuropsychologist, neurophysiologist, neuroimaging (magnetic resonance imaging) specialist, genetic epidemiologist, molecular genetic specialist, genetic statistician, and biostatisticians. This team has sound mutual trust base on the experience of being working together and attending regular research meeting for the part several years under the leadership of the principal investigator of this PPG.