Singapore passport holders do not need visa to China for 15 days for sightseeing or business. But if want to stay for 30 days, visa is required to processed through Chinese Visa Application Service Center in Singapore in advance. If you only need to enter China for once, a single entry is enough. The visa fee is GST 50. Non-Singapore citizens shall provide documents that entitle them to reside for an extended period of time in the SPR,WP,EP,STP,DP. Temporary visitors to Singapore should apply for a Chinese visa in their own country. For tourist purpose, no approval is required by the center unless the embassy asks for it.