A letter urging for the legalization of same-sex marriage has been sent to deputies of the National People's Congress (NPC), Southern Metropolis reported Wednesday.

"Some of our children have been living with their partners for nearly 10 years. They love each other. But they cannot sign their names legally when their partners need an operation," said the letter, which was written by PFLAG China (Parents and Friends of Lesbians and Gays of China) and represented more than 100 gay parents.

Ma Yu Yu (L) and Elsie Liao kiss outside a marriage registry office before being denied, in Beijing, Feb 25, 2013. [Photo/CFP]

The organization said it will communicate with deputies from South China's Guangdong province who are able to promote the legalization of gay marriage during the NPC this year.

The letter underlines the problems that gay couples in China face, such as adoption, inheritance and purchasing properties. It calls for early amendment of the Marriage Law to include the right of marriage for gays.

PFLAG China is a non-profit organization promoting understanding between homosexuals and their families, eliminating discrimination against gays and advocating equal civil rights for them. It was founded in Guangzhou, capital of Guangdong in June 2008.