Central administration reform divided administrative agencies into ministries according to their character to make the administration effective. The former central administration from Ayutthaya to King Rama V which consisted of Interior, Defense, Capital, Palace, Finance and Cultivation was reorganised. This was because the division of the central administration into 6 sections was not effective enough to keep up with the development of the country, the increasing number of government officers and the growing population. King Rama V then founded additional ministries. By royal command new forms of ministries were established and ministers whose authority and responsibility were allocated proportionately as follows:

1. The Ministry of Interior was responsible for the Northern provinces and Laos (in the early period) Later all provinces were put under the control of the Ministry of Interior.
2. The Ministry of Defense was responsible for Southern and Eastern provinces and Malaya. After power was transferred to the Ministry of Interior to control all provinces, the Ministry of Defense was responsible for controlling the Kingdom's army.
3. The Ministry of Foreign Affairs (Krom Ta) was responsible for foreign affairs.
4. The Ministry of Royal Household was responsible for palace affairs.
5. The Metropolitan Ministry (Nakornban) Krom Surasavadi was responsible for the police force and conscription.
6. The Ministry of Agriculture was responsible for agriculture, trade, forestry and mining.
7. The Ministry of Finance responsible for finance, revenues, and expenditures of the country.
8. The Ministry of Justice was responsible for gathering the courts which used to be dispersed around different departments and all the civil, criminal, metropolitan and appeal courts into one place.
9. The Ministry of War was responsible for managing the Army and the Navy.
10. The Ministry of Public Work was responsible for education, hospitals and monastery patronage.
11. The Ministry of Public Construction was responsible for the construction of roads, canals, railways; the Post and Telegram, and mechanical work.
12. The Ministry of Privy Seal was responsible for the royal privy seal, royal decrees, regulations and all official documents.

When the declaration of rearrangement of ministries was passed, ministers were appointed and two former positions of co-prime ministers which were the co-prime minister for Civil Affairs and the co-prime ministers for Military Affairs as well as four chief-ministers were abolished. The new positions of ministers were equal and together they formed the council of Ministers or Luk-Kun-Na-Sala, Later, there was an integration and reorganisation of ministries. By the end of King Rama V's reign, there were 10 ministries left, that is, Interior, Defense, Metropolitan, Foreign Affairs, Treasury, Royal Household, Agriculture, Justice, Civil Construction and Public Work.

In terms of restoration of the country, King Rama V greatly contributed to the prosperity of the country as, for example:

1. The Military: Realising the importance of soldiers to the nation and national defense, he had the army organised and trained in European style and sent his sons to study military science in Europe to bring back modern knowledge that could be adapted and applied to the Thai military. The Army and Navy were also inaugurated.
2. The Metropolitan Police Force: Local Police forces were set up in the provinces to be able to fully maintain peace and eliminate crime.
3. Finance: In terms of taxation, a new method was set up which lessened the inefficiency of tax collection due to the use of individual discretionary powers. Under the new taxation system, the government was directly responsible for tax collection. Since then, national revenue steadily increased. The king also had the Ministry of Finance print banknotes for more convenient transportation and safety.

   In terms of public welfare, the King set up a committee in charge of building hospitals such as Sirirat Hospital, Bangrak Hospital, the Mental Hospital and nurseries. Moreover, doctors were sent out to vaccinate against smallpox and to cure cholera. In 1912 A.D. the Waterworks was established but did not begin to operate until the reign of King Rama VI (1932 A.D.). In 1904 A.D., the Vachirayan Library was founded in Phra Nakhon province and was directly responsible to the Royal Thai Academic Council. Ho Phra Montien Tam and Ho Phra BuddhaSankla were annexed to this new library.

4. Communications were improved. In 1891 A.D. he built railroads to facilitate trade and communication. He opened the Bangkok-Nakhon Ratchhasima railway line. The inaugural opening of this line was in 1896 A.D..for the section of Bankok-Ayutthaya. The whole line was finished in 1913 A.D.

   In 1881 A.D., King Rama V set up the postal services for the first time and later made it a department in 1883 A.D. The Postal and Telegraph Service was later extended to several provinces to facilitate public communication.

5. Education was widely promoted and expanded. The first school was established in the Grand Palace to educate royal and officials' children and then the first State school was established in Mahanparam Temple.

   In 1892 A.D., The Ministry of Public Work was founded. It was responsible for the national scheme of education, the establishment of teacher training colleges, the extension of education to the people as well as for dispatching Thai students to study overseas in order to bring back modern knowledge and technology to develop the country.