Four sensitive and selective spectrophotometric and spectrofluorimetric methods were developed for the quantitative determination of Asenapine maleate (AS) in presence of its oxidative degradate. The first method derivative spectrophotometry depending on the measuring the peak of amplitudes of second and third derivative curves at 250,275 and 294 nm in case of 2D and at 259, 284 and 301 nm in case of 3D. The second method ratio Difference Spectrophotometry (RD) measuring the difference in absorbance between 261 and 291 nm. The third method Derivative Ratio (1DD) measuring the first derivative of ratio spectra at 272, 303 and 318 nm where no contribution of the degradate. The fourth method was depending on measuring the native florescence at λem 314 when exited at 270 nm. The linearity was obtained in concentration range 20-200 μg/ml for the 3 spectrophotometric methods while from 1-10 μg/ml for fluorimetric method. The 4 suggested methods can be applied for purity testing, stability studies, quality control and routine analysis of the proposed drug in pure and dosage form.