A novel powder metallurgy (P/M) material with high wear resistance is developed in orderto decrease the wear and lubricant-leakage of a diesel engine valve guide. The friction and wear tests ofthis material are conducted. It indicates that the wear resistance of the newly developed P/M materialhas been improved and much better than that of the formerly used alloy steel. Moreover, three differentsealing structures are designed and theoretically analyzed with respect to the characteristic of hydro-dynamic sealing. Through comparative experiments of component leakage and engine run-in for dif-ferent valve guide structures, it proves that the structure with a machined sealing groove but not in-stalled with a seal-ring cannot only reduce the specific lubricant consumption (SLC) of cylinder head,but also decrease the wear of valve stem and valve guide. A novel powder metallurgy (P / M) material with high wear resistance is developed in orderto decrease the wear and lubricant-leakage of a diesel engine valve guide. The friction and wear tests of this material are conducted. It indicates that the wear resistance of the newly developed P / M materialhas been improved and much better than that of the formerly used alloy steel. Moreover, three differentsealing structures are designed and theoretically analyzed with respect to the characteristic of hydro-dynamic sealing. -in for dif-ferent valve guide structures, it proves that the structure with a machined sealing groove but not in-stalled with a seal-ring can not only reduce the specific lubricant consumption (SLC) of cylinder head, but also decrease the wear of valve stem and valve guide.