Plasma photonic crystals (PPCs) have been a hot research topic in the band gap (BG) material field in recent years due to their unique advantages,such as the feasibility of changing the parameters and hence the properties of the materials with respect to traditional photonic crystals (PCs).In this paper,we focus mainly on the effects of some types of defects introduced in PPCs on the changes in BG characteristics of microwave (MW) transmittance.The research is carried out using numerical simulation with a one-dimensional finite-difference time-domain (FDTD) method,and six types of defects,including a lattice-constant defect,radii-ratio defect,additional-column defect,column-width defect,plasma-frequency defect,and electron-collision-frequency defect,are concerned.It transpires that introducing a defect in a PPC in different manners may realize the symmetric change,altemative change,shifting,generating,transforming,disappearing,and attenuating of BGs in transmittance spectra,which has great potential for the manufacture of spatiotemporal-controllable MW materials and devices with more feasible modulating functions.