How often will I be dealt a pocket pair?

Approximately once every 17 hands,anyone having different ideas?

If you're referring to being dealt a pocket pair (a pair in your two hole cards) in Texas Hold'em, the probability is well known.
There are 13 possible pocket pairs (AA, KK, QQ, ..., 22).
Out of the 1,326 possible two-card starting hand combinations, 78 are pocket pairs.
Therefore:
Probability: 78/1,326 ≈ 5.88%
This is approximately 1 out of every 17 hands (more precisely, once every 17.0 hands on average).
This means that:
Over 100 hands, you would expect to be dealt about 5.9 pocket pairs.
Over 1,000 hands, about 59 pocket pairs.
In a 500-hand session, around 29–30 pocket pairs.