Video streaming over wireless network is a challenging task due to high packet loss rate, burst packet loss, low available bandwidth, and so on. To improve the quality of transmission, Forward Error Correction (FEC) is a common technique to protect data loss by redundant packets. Today there are various kinds of FEC to explore how to adaptively adjust the redundant packet amount to overcome source error and loss. Block size and packet size of FEC are seldom considered together. However, when the block size is smaller, the tolerable error rate would be higher; and the impact on the quality of video streaming is greater when the smaller size of packets is used. Therefore, in this paper, we proposed an idea called "Dynamically Adjust Transmission Block Size and Packet Size FEC (DABSPS)" to explore appropriate block size and packet size to reduce the impact of packet loss in video streaming. The simulation results show that our methods can improve the decodable rate of slices and archive significant effectiveness of FEC.