Abstract: Although more and more PDC bits are used in drilling operation, but the results of drilling in the hard and soft interbedded formation are not desired. This paper presents the PDC bits with the satisfactory testing result in the multi-interbedded formation. In comparison with H517 roller bits used in the same block and the same interval, PDC bits have increased penetration rate by 30% and footage by 2 times, and have reduced cost by 20%. PDC bits also have advantages of deviation control and hole straightening. The PDC bits will play a significant role in speeding up the field exploration and production and/or in reducing drilling cost.