Abstract: The problems of adaptive nonparametric detectors are considered. The major reason behind the increasing engineering interest in nonparametric signal detectors is their ability to maintain CFAR (Constant-False-Alarm-Rate) at the detector output for a broad class of noise distributions. The false alarm probability (Pfa) is not constant, when the input noise is not the sequence of IID (Identical Independent Distribution) variance. In order to maintain CFAR the weight of the detection range cell of the detector can be changed continuously by different output value of IIR filter for measuring the correlation coefficient of the input noise. The closed form expressions for detection probability (Pd) and Pfa of the weighted nonparametric detectors are derived. The ARE (Asymptotic Relative Efficiency) of the detectors is investigated. finally, the detection performance of the adaptive nonparametric detector is determined for a finite number of observations.