The resolution of the third plenary session of 18th CPC Central Committee put forward the implementation of tax revenue legal principle for the first time. It further improves the fiscal and taxation law system in China, but the resolution did not mention the legalism of fiscal expenditure. China’s current legal provisions on the financial expenditure are very insufficient, because of the lack of legal provisions and disordered and rudderless financial power in real life. Since fiscal expenditure is involved more and more widely in every social field, is evidently characterized by publicity and authority, and is related to the redistribution of fundamental social and economic resources, the legal principles of fiscal expenditure are expected to be established and the legal system of fiscal expenditure is to be improved so that they will be standardized. More attention should be paid to financial democracy, financial transparency, and expenditure monitoring mechanism.