The current diagnosis of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) relies on laboratory-based tests since its clinical features are nonspecific, unlike other respiratory pathogens. Therefore, the development of a rapid and simple method for on-site detection of SARS-CoV is crucial for the identification and prevention of future SARS outbreaks. In this study, a simple colorimetric and multiplex loop-mediated isothermal amplification (LAMP) assay was developed to rapid screening of severe acute respiratory syndrome-associated coronavirus (SARS-CoV). It can be visually detected based on color change and monitored in real-time with fluorescent signals. The performance of this assay, based on six primers targeting open reading frame (ORF1b) and nucleocapsid (N) genes located in different regions of the SARS-CoV, was compared with real-time RT-PCR assay using various concentrations of target genes. The detection limit of the LAMP assay was comparable to that of real-time RT-PCR assay and therefore a few target RNA to 10⁴-10⁵ copies could be detected within a short period of time (20–25 min). In addition, we established a multiplex real-time LAMP assay to simultaneously detect two target regions within the SARS-CoV genome. Two target sequences were amplified by specific primers in the same reaction tube and revealed that it was able to detect down to 10⁵ copies. The standard curve had a linear relationship with similar amplification efficiencies. The LAMP assay results in shorter “sample-to-answer” time than conventional PCR method. Therefore, it is suitable not only for diagnosis of clinical test, but also for surveillance of SARS virus in developing countries.