I study in China, I want to have my mother and 3 younger siblings there. What type of China visa would they require to stay?

Your mother and 3 younger siblings can apply for Tourist Visa for family visit (L visa), you need to send them an invitation letter, the copy of your passport and Chinese residence permit (Student Visa holders are obliged to apply for residence permit at the local public security bureau within a month after entering China). They just need to provide their passports, passport photos, filled visa application forms and the relationship certificate.