Oil analysis is an effective method to monitor the wear status of the heavy load gear system.The data of wear particles concentration（WPC）

acid number

viscosity and water content are gasped by oil analysis

which show the wear status of the gear system.So

the grey correlation equations and the grey relevant dynamic matrix are constructed between the wear particle concentration and the lubricating oil chemical indexes.And a research of the dynamic tendency of grey correlation degree

which is between the wear particle concentration and the lubricating oil chemical indexes in every monitor time is carried out

according to the equation and the matrix.And the research shows that the dynamic tendency between the lubrication condition of equipments in every monitor time and the quality of lubricating oil is intuitive reflected by the grey relevant dynamic matrix.The tendency data can become the theoretical basis for the suitability judgment of lubricating oil

and further

it can help for making a scientific cycle of changing oil.The result can help for the judgment of distinguishing the wear particles in ferrography and wear condition of equipment.