A trust deployment scheme based on layered idea was given for grid environment

which reduced the man-agement costs of system.The fine-grain trust model was proposed which was based on interaction capability and honesty ability.It enhanced the rationality of the model.At the same time

4 influencing factors about trust transitivity were dis-cussed

such as cycle path

path length threshold

node honesty threshold and further trust information.On this condition

the trust transitivity algorithm for grid was studied which was based on depth-first traversal.Example and experimental results show that the model and algorithm are feasible and correct.