  We investigate the spontaneous emission from an inverted Y-type atomic system
coupled by three coherent fields. We use the Schr\"{o}dinger equation to
calculate the probability amplitudes of the wave function of the system and
derive an analytical expression of the spontaneous emission spectrum to trace
the origin of the spectral features. Quantum interference effects, such as the
spectral line narrowing, spectrum splitting and dark resonance are observed.
The number of spectral components, the spectral linewidth, and relative heights
can be very different depending on the physical parameters. A variety of
spontaneous emission spectral features can be controlled by the amplitudes of
the coupling fields and the preparation of the initial quantum state of the
atom. We propose an ultracold atomic $^{87}Rb$ system for experimental
observation.
