National unity is the significant symbol of national security and social stability, so the guarantee of good national unity must coordinate national relations well. This paper takes the regulation of the national relations in the National Regional Ethnic Autonomy Law as the research perspective, and combines with the relevant situations of the enforcement inspection of National Regional Ethnic Autonomy Law carried out by the standing committee of the National People's Congress to prove the significance of adjusting national relations by law to promote national unity. Considering the specific enforcement of the Law, the current trends and dilemma of China’s national unity, it analyzes the specific regulations about adjusting of national relations of the Law and puts forward some suggestions for coordinating and promoting national unity.