We present a result of a blind search for [CII] 158 $mu$m emitters at $zsim 4.5$ using ALMA Cycle~0 archival data. We collected extra-galactic data covering at 330-360 GHz (band~7) from 8 Cycle~0 projects from which initial results have been already published. The total number of fields is 243 and the total on-source exposure time is 19.2 hours. We searched for line emitters in continuum-subtracted data cubes with spectral resolutions of 50, 100, 300 and 500 km/s. We could not detect any new line emitters above a 6-$sigma$ significance level. This result provides upper limits to the [CII] luminosity function at $zsim 4.5$ over $L_{rm [CII]} sim 10^8 - 10^{10} L_{odot}$ or star formation rate, SFR $sim$ 10-1000 M$_{^odot}$/yr. These limits are at least 2 orders of magnitude larger than the [CII] luminosity functions expected from the $z sim 4$ UV luminosity function or from numerical simulation. However, this study demonstrates that we would be able to better constrain the [CII] luminosity function and to investigate possible contributions from dusty galaxies to the cosmic star-formation rate density by collecting Cycle~1+2 archival data as the ALMA Patchy Deep Survey.
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