We report the identification of four millimeter line emitting galaxies with the Atacama Large Milli/submillimeter Array ( ALMA ) in SSA22 Field ( ADF22 ) . We analyze the ALMA 1.1 mm survey data , with an effective survey area of 5 arcmin ^ { 2 } , a frequency range of 253.1–256.8 and 269.1–272.8 GHz , angular resolution of 0 ^ { \prime \prime } .7 and RMS noise of 0.8 mJy beam ^ { -1 } at 36 km s ^ { -1 } velocity resolution . We detect four line emitter candidates with significance levels above 6 \sigma . We identify one of the four sources as a CO ( 9-8 ) emitter at z = 3.1 in a member of the proto-cluster known in this field . Another line emitter with an optical counterpart is likely a CO ( 4-3 ) emitter at z = 0.7 . The other two sources without any millimeter continuum or optical/near-infrared counterpart are likely to be [ C ii ] emitter candidates at z = 6.0 and 6.5 . The equivalent widths of the [ C ii ] candidates are consistent with those of confirmed high-redshift [ C ii ] emitters and candidates , and are a factor of 10 times larger than that of the CO ( 9-8 ) emitter detected in this search . The [ C ii ] luminosity of the candidates are 4 - 7 \times 10 ^ { 8 } ~ { } L _ { \odot } . The star formation rates ( SFRs ) of these sources are estimated to be 10 - 20 ~ { } M _ { \odot } ~ { } yr ^ { -1 } if we adopt an empirical [ C ii ] luminosity - SFR relation . One of them has a relatively low-S/N ratio , but shows features characteristic of emission lines . Assuming that at least one of the two candidates is a [ C ii ] emitter , we derive a lower limit of [ C ii ] -based star formation rate density ( SFRD ) at z~ { } \sim~ { } 6 . The resulting value of > 10 ^ { -2 } M _ { \odot } yr ^ { -1 } Mpc ^ { -3 } is consistent with the dust-uncorrected UV-based SFRD . Future millimeter/submillimeter surveys can be used to detect a number of high redshift line emitters , with which to study the star formation history in the early Universe .