Intra interpolation filters for intra angular prediction play an important role in the coding performance. In the intra angular prediction of VVC, which is being standardized by the joint video coding expert team (JVET), block-size based switchable interpolation filters between 4-tap cubic and Gaussian interpolation filters is being studied. Although the two filters have different frequency characteristics, block size-based criteria are insufficient to represent the reference sample characteristics. In this manuscript, switching criteria based on both the block-size and QP value are proposed to improve the coding performance. The experimental results show a -0.45% BD-rate gain compared with that by the VVC test model 2 for all intra conditions under the common test condition (CTC) in JVET.