Traveling To Guangzhou China

Hello Sir/ma'am,
I am from India this summer i am travelling to Guangzhou for a month.
My arrival will be at HK airport and then i will take a train to Guangzhou East .
so my Question is do i have to take any HK visa.
because my Return ticket will be after a month form HK .
but Till the period of my stay i will be in Guangzhou.