The Tourism Department's 2013 budget will rise to 2.7 billion baht from 1.7 billion this year as it seeks to attract more visitors to Thailand's attractions.
It also plans to seek a budget of 4.3 billion baht to continue its projects in the 2014 fiscal year.
The tourism site development plan for 2012-14, which will require a budget of 8 billion baht, will focus on eight clusters covering 61 provinces.
About 60% of the cash will be used to upgrade sites and the rest for marketing campaigns, said deputy director general Anupap Gaesornsuwan.
After criticism by private operators about work delays and no concrete projects in 2012, Mr Anupap said major projects take 8-12 months to develop.
"The time-consuming budget disbursement has been the main cause of project delays," he said.
However, the department expects major projects such as a six-month scheme to light up the Chao Phraya River to start early next year.
Mr Anupap said it would focus marketing campaigns on domestic tourism, which is targeted to enjoy growth of about 6% next year.
This year, domestic tourism will increase to 112 million trips producing revenue of 500 billion baht. The department said international tourist arrivals in the first 11 months increased by 13.57% to 19.761 million. It projects arrivals will reach 21.8 million visitors by year-end, generating revenue of 930 billion baht.