Offenders now face up to 20 years in jail and a fine of 40,000 baht ($1,156; £620) for raping their spouses - the same penalty that exists for non-marital rape.
The bill also allows for women and homosexuals to be prosecuted for rape.
The previous law had defined a rapist as a person who rapes a woman who is not his wife.
"The previous law was discriminatory," said Kingkaew Inwang, deputy director of the Office of Women's Affairs and Family Development.
"Now, everybody is being treated equally under the new law," she told the Agence France Presse news agency.
^ Back to top | BBC Sport Home | BBC Homepage | Contact us | Help | ©
~RS~q~RS~~RS~z~RS~08~RS~)