Do I need any transit visa for a transit in Beijing?

I'm travelling from KUL to Beijing on 3rd July (11:40pm) and arriving at Beijing Capital Airport on 4th July (06:00am). From there I will take a transit flight to Ulaanbaatar (08:35am). Do I need any transit visa for this? On 12th July I will be flying from Ulaanbaatar to Beijing for 3 days visit which I will apply for the visa. My concern was the Immigration in China will consider my transit to Ulaanbaatar as though I use the visa already. This happen in my previous trip. Please advise.