The one-way permit system was introduced in 1982. Over 90 percent of permit holders come to Hong Kong to join spouses or parents.
The Chinese authority and the Joint Liaison Group increased the daily quota from 75 to 105 in 1993.
Among the extra 30 places, half will go to children born of Hong Kong residents.
According to the Basic Law, these children will obtain permanent residency automatically on July 1, 1997.
Assistant Secretary for Security Ingrid Ho explained the reason for further increasing the quota.
"Among the 300,000 Mainland children born by Hong Kong residents, about 64,000 would be eligible for permanent residency.
"Owing to the increasing number of cross-border marriages these last few years, the actual number will likely be much larger," said Miss Ho.
Many legislators worried if the daily quota of 15 is not increased, it would not be able for Hong Kong to absorb all eligible children before 1997. Legislator Wong Wang Fat anticipated the possible result this way:
"There will be a rampant influx of illegal immigrants shortly after the political handover," said Mr. Wong. "As the Basic Law has entitled Mainland-born children to permanent residency, we cannot repatriate them even if they come illegally.
"Yet, we can solve this problem by expanding the (daily) quota. Therefore, they can come to Hong Kong in an orderly way within these two years.
Legislator Elsie Tu also criticised the present quota system.
"Even though the quota has been increased for Mainland children, their mothers cannot come together with them."
She described the situation as a contradiction of human rights principles.
"It is unreasonable to allow children to reside in Hong Kong while leaving their mothers in China.
"Also, I think the permit should be issued on a family basis instead of an individual one," she added.
Mrs. Tu suggested setting a priority in allocating the quota to Mainlanders.
Said she: "Firstly, the quota should be allocated to those families with husbands born in Hong Kong.
"Coming second are families of citizens who hold permanent Hong Kong residency.
"At present, there are 70,000 children in Hong Kong whose mothers are illegal immigrants. I think the rest of the quota should go to them."
Mr. Chan Wai To, a senior lecturer in the Division of Humanities and Social Sciences at the City University of Hong Kong, said, "From the standpoint of Mainlanders, increasing the one-way permit quota is certainly desirable. However, we have to assess our social resources beforehand.
"It's imperative for the government to have interdepartmental co-ordination so as to minimize the potential social problems in the future," he added.
Taking education as an example, the increase would bring more school age immigrants into Hong Kong.
Secretary for Security Alistair Asprey has said that, of all eligible children, 51,000 are aged under 10.
According to the Education Department, the additional expenses for these children would be around $400 million for the first five years, plus capital expenditures of more than $100 million.
Besides, services are needed to assist these new children immigrants to adapt to the new environment.
Mrs. Fong Wong Mei Wah of Kwai Fong came to Hong Kong about two months ago with her 4-year-old son, Fong Chun Hei. She pointed out the problems faced by her son.
"Chun Hei's greatest problem is the language barrier. As he cannot speak Cantonese, he can't understand what the teachers say and can't communicate with his classmates," said Mrs. Fong.
Therefore, resource classes, peripatetic teaching services and resource teaching centres are needed to provide counselling services and remedial teaching for the Mainland children.
Yet, no matter how limited social resources Hong Kong may have been up to now, the Government will not have a final say on future increases in the quota: The situation is out of their hands.
Miss Ho, the assistant secretary for security, explained, "The number for the quota is decided by the Chinese authorities. Yet they will consult the Hong Kong government on the categories of people qualified to the quota.