The small signal rf impedance of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta// step edge junction rf SQUIDs operating in a strongly nonhysteretic mode has been measured. The phase dependent inductance L/sub J/(/spl phi/) and the current phase relation I/sub p/(/spl phi/) of step-edge junctions embedded in SQUIDs are calculated from measurement data following the Vincent-Deaver approach. Two of three junctions investigated revealed a sinusoidal current phase relation. I/sub p/(/spl phi/) of the third junction seemed to be non-sinusoidal and hysteretic. A model explaining the origin of the non-sinusoidality of I/sub p/(/spl phi/) is proposed