Eight ultra-high performance concrete T-beams subjected to bending were tested to investigate their cracking moments and cracking characteristics and evaluate the formulas for cracking moment and crack width specified in existing design codes. The test results show that the degree of prestress has a great impact on the cracking moment; the bending cracks are dense and fine, the development of the maximum crack width is slow at the early stage of loading and speeds up remarkably when the reinforcements reach to yield strength. Predicating the cracking moment and maximum crack width by existing code formulas will lead to overly conservative results. The modified formulas of cracking moment and crack width are suggested for ultra-high performance concrete beams by introducing the anti-cracking effect coefficient and crack-correction coefficient respectively, and the calculated values by the suggested formulas agree well with the test results.