  In this paper we present the results of a detailed spectroscopic and
photometric analysis of the V=13$^m$.4 low-mass eclipsing binary NSVS 06507557
with an orbital period of 0.515 d. We obtained a series of mid-resolution
spectra covering nearly entire orbit of the system. In addition we obtained
simultaneous VRI broadband photometry using a small aperture telescope. From
these spectroscopic and photometric data we have derived the system's orbital
parameters and determined the fundamental stellar parameters of the two
components. Our results indicate that NSVS 06507557 consists of a K9 and an M3
pre-main-sequence stars with masses of 0.66$\pm$0.09 \Msun and 0.28$\pm$0.05
\Msun and radii of 0.60$\pm$0.03 and 0.44$\pm$0.02 \Rsun, located at a distance
of 111$\pm$9 pc. The radius of the less massive secondary component is larger
than that of the zero-age main-sequnce star having the same mass. While the
radius of the primary component is in agreement with ZAMS the secondary
component appers to be larger by about 35 % with respect to its ZAMS
counterpart. Night-to-night intrinsic light variations up to 0$^m$.2 have been
observed. In addition, the H$_{\alpha}$, H$_{\beta}$ lines and the forbidden
line of [O{\sc i}] are seen in emission. The Li{\sc i} 6708 \AA absorption line
is seen in most of the spectra. These features are taken to be the signs of the
classic T Tauri stars' characteristics. The parameters we derived are
consistent with an age of about 20 Myr according to the stellar evolutionary
models. The spectroscopic and photometric results are in agreement with those
obtained by theoretical predictions.
