A CONFRONTATION is looming in Kelantan between alcohol-drinking Chinese and the austere religious leader who heads the state Government. About 1,500 Malaysian Chinese are planning to attend a yum sing, or ''bottoms up'', party at the Chinese Chamber of Commerce in Kota Baru, the state capital, on August 6 to protest against new restrictions on drinking. In response, the state Government has threatened to impose a ban on liquor sales. The Chief Minister, Nik Abdul Aziz Nik Mat, who wants Muslims in Kelantan to observe strictly the teachings of Islam, including abstaining from alcohol, said his administration had been ''very considerate and accommodating'' where the needs of non-Muslims were concerned. But if the non-Muslim community persisted in ''threatening open defiance'', the Government might ban the sale of liquor altogether. Kelantan is controlled by Parti Islam, an opposition party in the federal parliament, which has been criticised by Prime Minister Datuk Seri Dr Mahathir Mohamad over its plans to introduce Islamic laws prescribing stoning, whipping and amputation for certain offences. The Kelantan Government renewed only 19 out of 30 liquor licences that expired on June 30 and decreed that, from July 1, non-Muslims must give local authorities a week's notice if they wanted to serve alcohol at social or religious functions. Announcing the yum sing party, the Malaysian Chinese Association (MCA), a member of Dr Mahathir's National Front coalition, said it would fight the issue in court if anyone was arrested for defying the state's new regulations. Lim Jit Keng, chairman of the MCA's Kelantan branch, said yum sing ceremonies required no one's permission. The deputy president of the MCA, Datuk Seri Lee Kim Sai, who is Minister of Health, said he had declined an invitation to attend the party because of his position but did not support the Kelantan Government's action. Speaking after launching a ''Healthy Living, Healthy Lifestyle 1993'' campaign, he said the Kelantan Chief Minister should understand that drinking alcohol was a Chinese custom. ''Moderate drinking is not necessarily harmful to health,'' he said.