To understand the variations that occurs in electrical parameters on doping potassium chromate (K2CrO4) in Poly- Methyl-methacrylate (PMMA), the authors have developed composite films by doping 1 %, 2 %, 5 % and 10 % K2CrO4 in PMMA by solution cast technique at room temperature. These samples were analysed for structural properties using XRD and FTIR. The dielectric parameters like real part and imaginary part of dielectric constant (ε′ and ε′′), ac conductivity (σ) and real part and imaginary part of electric modulus (M'andM'') prepared of specimen have been evaluated from the electrical parameters obtained using Impedance analyzer WANN KERR. Both real and imaginary component of the dielectric permittivity decrease with increase in the frequency in the range 102 Hz to 105 Hz and increase on increasing the concentration of K2CrO4. AC conductivity shows an increase with increase in frequency and concentration of K2CrO4. M'andM'' the segmental movement of the polymer chain dominating the dielectric properties.