Is there any train from Hong Kong to Guangzhou? How much time needed and cost?

Yes, there are trains from Hung Hom Railway Station to Guangzhou East Railway Station. The train is available from 7:25 to 20:01, and the duration is about 2 hours. The deluxe seat costs HKD 230, while the first-class seat costs HKD 190 for an adult. Children between five to ten years old can enjoy half price, and children younger than five years old can take the train free of charge. :)