Abstract: With the model of decision tree, we examined the cost and benefit-cost ratios (BCR) of three strategies: vaccinating everyone, screening followed by vaccination anb no vaccination for some age groups of urban and rural people in china. According to the analyses of cost anb threshold, those whose accumulative positive rates of hepatitis B virus markers(HBYM) is lower than 40% should be vaccinated directly without screening and should be screened fcllowed by vaccination if their rates of HBYM is higher than 40% But the results of the benefit analysis were shown that the BCR of vaccination decreased from the old to neonate, so the age groans of the priority for vaccination is the young, especialy newborn when products of the vaccine is shortage currently. The sensitivity of all parameters in the model was also for mulated.