Abstract: We investigate three equivalent sufficient conditions for weak laws of large numbers （WLLN）for sequences of identically distributed NA （Negatively Associated） variables （IDNA）. One example is given to show that these conditions are not equivalent to WLLN for IDNA sequences. The results illustrate the differences of conditions for WLLN between IDNA and IID sequences. However, it should be noted that IDNA and IID sequences have the same Marcinkiewicz strong laws of large numbers.