With the increase of strengthening degree, the parts of vehicle engines are required to bear much heavier mechanical and thermal loads. Great importance is attached to the Low Heat Rejection (LHR) technique to reduce the thermal loads and heat rejection in the field of internal combustion engines. Bearing heavy mechanical and thermal loads, cylinder heads are the most complicated parts and the key point of the LHR technique application in engines. This paper presents the researching work of the LHR cylinder head and its structure. A three-dimensional Finite Elements Analysis (FEA) of the cylinder head was offered and a large amdunt of significant data were obtained to find out the teniperatures field distribution a n d comprehensive stresses field distribution. LHR cylinder heads have greatly reduced the amount of heat rejection. This paper may provide some insights for the LHR cylinder head's designs.