The generalized distribution function is used to investigate the effects of loss-cone and temperature anisotropy on the cross-field-current-driven electrostatic instabilities, i.e. the modified two-stream instability, the ion-acoustic instability and the electron cyclotron drift instability. These effects are important only when (k is the wave number and ρe the electron gyroradius). It is seen that non-Maxwellian plasmas with distribution index J≥1, can sustain fast-growing waves even in the region of k-space which is stable for a Maxwellian plasma. Moreover, when λ ∼ 1, the temperature anisotropy is found to have a destabilizing effect on.the modified-two-stream instability and on the ion acoustic instability.