Does PRC China passport holder tourist need to apply visa to enter Hong Kong?

I'm Singapore Permanent Resident and my parents are China resident, all of us are holding China passports. My parents are currently with me in Singapore, we'd like to have a 5 day trip to Hong Kong then coming back to Singapore. I'm not sure if we all need a visa to Hong Kong for such short trip and myself went to HK last year for a short trip without any visa application. Appreciate your advise!