In the beginning of this year

SARS（Severe Acute Respiratory Syndrome）broke out and spread in mainland of China

Hong Kong

Taiwan and other countries

regions successively. The world

especially China

pays high attentions on this public hygiene safety affair and takes various measures to prevent and control the further spreading of SARS.This work began in early April in this background.At this time

the SARS began to spread to Beijing and northern regions of China

but the situation in southern regions

such as Guangdong and Hong Kong is relative stable. The data about SARS spreading

special cases and sources in these regions are available.Through these information

we found the spreading characteristic of SARS has a distinct one besides other common ones

namely

jumped sperad between two points in long distance.This characteristic can not be singly described by the diffusion models for point sources. Pointed to this

a "fly dots"spreading model along transportation is put forward in this paper

which takes the vehicle as a scale and sets up SARS spreading model in the relative sealed vehicle. Based on this model

in a scale of the transportation

the spatial spreading of SARS due to flow of passengers is modeled. We simulatde the danger probability of SARS sperading

three cases reported in internet

and the affect of Beijing SARS epidemic situation to in Hebei province due to flow of passengers.The results show that this model meets the spacial spreading characteristic of SARS. Not only the vent

and disinfect and others measures affect SARS spreading in vehicle

but time is also an important factor to be considered. The SARS spread along transportation is affected by these regions’ population distribution

the SARS epidemic situation in the beginner affect the situation in the regions of the stops in a great degree. The results simulated by the models can be used to support the decision-making