If one was denied to get a visa, can she re-apply?

I'm from Philippines.I've been working in China for three years. Early this week, i let my sister applied a tourist busy in China Embassy in the Philippines so she can come and spend christmas with me.Sadly, she was denied to get a visa, without any comments.She submitted all the needed requirements but why she was denied and the embassy didn't say anything, just it's the officer's decision. Can she re-apply so she can come to China?Please response. Thank you.